diff --git a/.travis.yml b/.travis.yml
index c5c479d..192f67f 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -2,13 +2,10 @@ language: python
 dist: xenial
 sudo: true
 python:
-  - 3.7.2
-env:
-  global:
-    - PIPENV_VENV_IN_PROJECT=1
-    - PIPENV_IGNORE_VIRTUALENVS=1
+  - 3.9
 install:
-  - pip install -q -r requirements-dev.txt codecov
+  - pip install -q pipenv codecov
+  - pipenv sync --dev
 script:
   - flake8
   - pytest libpythonpro --cov=libpythonpro
diff --git a/Pipfile b/Pipfile
new file mode 100644
index 0000000..9f67740
--- /dev/null
+++ b/Pipfile
@@ -0,0 +1,16 @@
+[[source]]
+url = "https://pypi.org/simple"
+verify_ssl = true
+name = "pypi"
+
+[packages]
+requests = "*"
+
+[dev-packages]
+flake8 = "*"
+pytest = "*"
+coverage = "*"
+pytest-cov = "*"
+
+[requires]
+python_version = "3.9"
diff --git a/Pipfile.lock b/Pipfile.lock
new file mode 100644
index 0000000..b1f1e36
--- /dev/null
+++ b/Pipfile.lock
@@ -0,0 +1,237 @@
+{
+    "_meta": {
+        "hash": {
+            "sha256": "7baa139aae9609422df71378bbcada2889a0eee47b4d0c24f30e25f0a7d66f3a"
+        },
+        "pipfile-spec": 6,
+        "requires": {
+            "python_version": "3.9"
+        },
+        "sources": [
+            {
+                "name": "pypi",
+                "url": "https://pypi.org/simple",
+                "verify_ssl": true
+            }
+        ]
+    },
+    "default": {
+        "certifi": {
+            "hashes": [
+                "sha256:2bbf76fd432960138b3ef6dda3dde0544f27cbf8546c458e60baf371917ba9ee",
+                "sha256:50b1e4f8446b06f41be7dd6338db18e0990601dce795c2b1686458aa7e8fa7d8"
+            ],
+            "version": "==2021.5.30"
+        },
+        "charset-normalizer": {
+            "hashes": [
+                "sha256:0c8911edd15d19223366a194a513099a302055a962bca2cec0f54b8b63175d8b",
+                "sha256:f23667ebe1084be45f6ae0538e4a5a865206544097e4e8bbcacf42cd02a348f3"
+            ],
+            "markers": "python_version >= '3'",
+            "version": "==2.0.4"
+        },
+        "idna": {
+            "hashes": [
+                "sha256:14475042e284991034cb48e06f6851428fb14c4dc953acd9be9a5e95c7b6dd7a",
+                "sha256:467fbad99067910785144ce333826c71fb0e63a425657295239737f7ecd125f3"
+            ],
+            "markers": "python_version >= '3'",
+            "version": "==3.2"
+        },
+        "requests": {
+            "hashes": [
+                "sha256:6c1246513ecd5ecd4528a0906f910e8f0f9c6b8ec72030dc9fd154dc1a6efd24",
+                "sha256:b8aa58f8cf793ffd8782d3d8cb19e66ef36f7aba4353eec859e74678b01b07a7"
+            ],
+            "index": "pypi",
+            "version": "==2.26.0"
+        },
+        "urllib3": {
+            "hashes": [
+                "sha256:39fb8672126159acb139a7718dd10806104dec1e2f0f6c88aab05d17df10c8d4",
+                "sha256:f57b4c16c62fa2760b7e3d97c35b255512fb6b59a259730f36ba32ce9f8e342f"
+            ],
+            "markers": "python_version >= '2.7' and python_version not in '3.0, 3.1, 3.2, 3.3, 3.4' and python_version < '4'",
+            "version": "==1.26.6"
+        }
+    },
+    "develop": {
+        "atomicwrites": {
+            "hashes": [
+                "sha256:6d1784dea7c0c8d4a5172b6c620f40b6e4cbfdf96d783691f2e1302a7b88e197",
+                "sha256:ae70396ad1a434f9c7046fd2dd196fc04b12f9e91ffb859164193be8b6168a7a"
+            ],
+            "markers": "sys_platform == 'win32'",
+            "version": "==1.4.0"
+        },
+        "attrs": {
+            "hashes": [
+                "sha256:149e90d6d8ac20db7a955ad60cf0e6881a3f20d37096140088356da6c716b0b1",
+                "sha256:ef6aaac3ca6cd92904cdd0d83f629a15f18053ec84e6432106f7a4d04ae4f5fb"
+            ],
+            "markers": "python_version >= '2.7' and python_version not in '3.0, 3.1, 3.2, 3.3, 3.4'",
+            "version": "==21.2.0"
+        },
+        "colorama": {
+            "hashes": [
+                "sha256:5941b2b48a20143d2267e95b1c2a7603ce057ee39fd88e7329b0c292aa16869b",
+                "sha256:9f47eda37229f68eee03b24b9748937c7dc3868f906e8ba69fbcbdd3bc5dc3e2"
+            ],
+            "markers": "sys_platform == 'win32'",
+            "version": "==0.4.4"
+        },
+        "coverage": {
+            "hashes": [
+                "sha256:004d1880bed2d97151facef49f08e255a20ceb6f9432df75f4eef018fdd5a78c",
+                "sha256:01d84219b5cdbfc8122223b39a954820929497a1cb1422824bb86b07b74594b6",
+                "sha256:040af6c32813fa3eae5305d53f18875bedd079960822ef8ec067a66dd8afcd45",
+                "sha256:06191eb60f8d8a5bc046f3799f8a07a2d7aefb9504b0209aff0b47298333302a",
+                "sha256:13034c4409db851670bc9acd836243aeee299949bd5673e11844befcb0149f03",
+                "sha256:13c4ee887eca0f4c5a247b75398d4114c37882658300e153113dafb1d76de529",
+                "sha256:184a47bbe0aa6400ed2d41d8e9ed868b8205046518c52464fde713ea06e3a74a",
+                "sha256:18ba8bbede96a2c3dde7b868de9dcbd55670690af0988713f0603f037848418a",
+                "sha256:1aa846f56c3d49205c952d8318e76ccc2ae23303351d9270ab220004c580cfe2",
+                "sha256:217658ec7187497e3f3ebd901afdca1af062b42cfe3e0dafea4cced3983739f6",
+                "sha256:24d4a7de75446be83244eabbff746d66b9240ae020ced65d060815fac3423759",
+                "sha256:2910f4d36a6a9b4214bb7038d537f015346f413a975d57ca6b43bf23d6563b53",
+                "sha256:2949cad1c5208b8298d5686d5a85b66aae46d73eec2c3e08c817dd3513e5848a",
+                "sha256:2a3859cb82dcbda1cfd3e6f71c27081d18aa251d20a17d87d26d4cd216fb0af4",
+                "sha256:2cafbbb3af0733db200c9b5f798d18953b1a304d3f86a938367de1567f4b5bff",
+                "sha256:2e0d881ad471768bf6e6c2bf905d183543f10098e3b3640fc029509530091502",
+                "sha256:30c77c1dc9f253283e34c27935fded5015f7d1abe83bc7821680ac444eaf7793",
+                "sha256:3487286bc29a5aa4b93a072e9592f22254291ce96a9fbc5251f566b6b7343cdb",
+                "sha256:372da284cfd642d8e08ef606917846fa2ee350f64994bebfbd3afb0040436905",
+                "sha256:41179b8a845742d1eb60449bdb2992196e211341818565abded11cfa90efb821",
+                "sha256:44d654437b8ddd9eee7d1eaee28b7219bec228520ff809af170488fd2fed3e2b",
+                "sha256:4a7697d8cb0f27399b0e393c0b90f0f1e40c82023ea4d45d22bce7032a5d7b81",
+                "sha256:51cb9476a3987c8967ebab3f0fe144819781fca264f57f89760037a2ea191cb0",
+                "sha256:52596d3d0e8bdf3af43db3e9ba8dcdaac724ba7b5ca3f6358529d56f7a166f8b",
+                "sha256:53194af30d5bad77fcba80e23a1441c71abfb3e01192034f8246e0d8f99528f3",
+                "sha256:5fec2d43a2cc6965edc0bb9e83e1e4b557f76f843a77a2496cbe719583ce8184",
+                "sha256:6c90e11318f0d3c436a42409f2749ee1a115cd8b067d7f14c148f1ce5574d701",
+                "sha256:74d881fc777ebb11c63736622b60cb9e4aee5cace591ce274fb69e582a12a61a",
+                "sha256:7501140f755b725495941b43347ba8a2777407fc7f250d4f5a7d2a1050ba8e82",
+                "sha256:796c9c3c79747146ebd278dbe1e5c5c05dd6b10cc3bcb8389dfdf844f3ead638",
+                "sha256:869a64f53488f40fa5b5b9dcb9e9b2962a66a87dab37790f3fcfb5144b996ef5",
+                "sha256:8963a499849a1fc54b35b1c9f162f4108017b2e6db2c46c1bed93a72262ed083",
+                "sha256:8d0a0725ad7c1a0bcd8d1b437e191107d457e2ec1084b9f190630a4fb1af78e6",
+                "sha256:900fbf7759501bc7807fd6638c947d7a831fc9fdf742dc10f02956ff7220fa90",
+                "sha256:92b017ce34b68a7d67bd6d117e6d443a9bf63a2ecf8567bb3d8c6c7bc5014465",
+                "sha256:970284a88b99673ccb2e4e334cfb38a10aab7cd44f7457564d11898a74b62d0a",
+                "sha256:972c85d205b51e30e59525694670de6a8a89691186012535f9d7dbaa230e42c3",
+                "sha256:9a1ef3b66e38ef8618ce5fdc7bea3d9f45f3624e2a66295eea5e57966c85909e",
+                "sha256:af0e781009aaf59e25c5a678122391cb0f345ac0ec272c7961dc5455e1c40066",
+                "sha256:b6d534e4b2ab35c9f93f46229363e17f63c53ad01330df9f2d6bd1187e5eaacf",
+                "sha256:b7895207b4c843c76a25ab8c1e866261bcfe27bfaa20c192de5190121770672b",
+                "sha256:c0891a6a97b09c1f3e073a890514d5012eb256845c451bd48f7968ef939bf4ae",
+                "sha256:c2723d347ab06e7ddad1a58b2a821218239249a9e4365eaff6649d31180c1669",
+                "sha256:d1f8bf7b90ba55699b3a5e44930e93ff0189aa27186e96071fac7dd0d06a1873",
+                "sha256:d1f9ce122f83b2305592c11d64f181b87153fc2c2bbd3bb4a3dde8303cfb1a6b",
+                "sha256:d314ed732c25d29775e84a960c3c60808b682c08d86602ec2c3008e1202e3bb6",
+                "sha256:d636598c8305e1f90b439dbf4f66437de4a5e3c31fdf47ad29542478c8508bbb",
+                "sha256:deee1077aae10d8fa88cb02c845cfba9b62c55e1183f52f6ae6a2df6a2187160",
+                "sha256:ebe78fe9a0e874362175b02371bdfbee64d8edc42a044253ddf4ee7d3c15212c",
+                "sha256:f030f8873312a16414c0d8e1a1ddff2d3235655a2174e3648b4fa66b3f2f1079",
+                "sha256:f0b278ce10936db1a37e6954e15a3730bea96a0997c26d7fee88e6c396c2086d",
+                "sha256:f11642dddbb0253cc8853254301b51390ba0081750a8ac03f20ea8103f0c56b6"
+            ],
+            "index": "pypi",
+            "version": "==5.5"
+        },
+        "flake8": {
+            "hashes": [
+                "sha256:07528381786f2a6237b061f6e96610a4167b226cb926e2aa2b6b1d78057c576b",
+                "sha256:bf8fd333346d844f616e8d47905ef3a3384edae6b4e9beb0c5101e25e3110907"
+            ],
+            "index": "pypi",
+            "version": "==3.9.2"
+        },
+        "iniconfig": {
+            "hashes": [
+                "sha256:011e24c64b7f47f6ebd835bb12a743f2fbe9a26d4cecaa7f53bc4f35ee9da8b3",
+                "sha256:bc3af051d7d14b2ee5ef9969666def0cd1a000e121eaea580d4a313df4b37f32"
+            ],
+            "version": "==1.1.1"
+        },
+        "mccabe": {
+            "hashes": [
+                "sha256:ab8a6258860da4b6677da4bd2fe5dc2c659cff31b3ee4f7f5d64e79735b80d42",
+                "sha256:dd8d182285a0fe56bace7f45b5e7d1a6ebcbf524e8f3bd87eb0f125271b8831f"
+            ],
+            "version": "==0.6.1"
+        },
+        "packaging": {
+            "hashes": [
+                "sha256:7dc96269f53a4ccec5c0670940a4281106dd0bb343f47b7471f779df49c2fbe7",
+                "sha256:c86254f9220d55e31cc94d69bade760f0847da8000def4dfe1c6b872fd14ff14"
+            ],
+            "markers": "python_version >= '3.6'",
+            "version": "==21.0"
+        },
+        "pluggy": {
+            "hashes": [
+                "sha256:15b2acde666561e1298d71b523007ed7364de07029219b604cf808bfa1c765b0",
+                "sha256:966c145cd83c96502c3c3868f50408687b38434af77734af1e9ca461a4081d2d"
+            ],
+            "markers": "python_version >= '2.7' and python_version not in '3.0, 3.1, 3.2, 3.3'",
+            "version": "==0.13.1"
+        },
+        "py": {
+            "hashes": [
+                "sha256:21b81bda15b66ef5e1a777a21c4dcd9c20ad3efd0b3f817e7a809035269e1bd3",
+                "sha256:3b80836aa6d1feeaa108e046da6423ab8f6ceda6468545ae8d02d9d58d18818a"
+            ],
+            "markers": "python_version >= '2.7' and python_version not in '3.0, 3.1, 3.2, 3.3'",
+            "version": "==1.10.0"
+        },
+        "pycodestyle": {
+            "hashes": [
+                "sha256:514f76d918fcc0b55c6680472f0a37970994e07bbb80725808c17089be302068",
+                "sha256:c389c1d06bf7904078ca03399a4816f974a1d590090fecea0c63ec26ebaf1cef"
+            ],
+            "markers": "python_version >= '2.7' and python_version not in '3.0, 3.1, 3.2, 3.3'",
+            "version": "==2.7.0"
+        },
+        "pyflakes": {
+            "hashes": [
+                "sha256:7893783d01b8a89811dd72d7dfd4d84ff098e5eed95cfa8905b22bbffe52efc3",
+                "sha256:f5bc8ecabc05bb9d291eb5203d6810b49040f6ff446a756326104746cc00c1db"
+            ],
+            "markers": "python_version >= '2.7' and python_version not in '3.0, 3.1, 3.2, 3.3'",
+            "version": "==2.3.1"
+        },
+        "pyparsing": {
+            "hashes": [
+                "sha256:c203ec8783bf771a155b207279b9bccb8dea02d8f0c9e5f8ead507bc3246ecc1",
+                "sha256:ef9d7589ef3c200abe66653d3f1ab1033c3c419ae9b9bdb1240a85b024efc88b"
+            ],
+            "markers": "python_version >= '2.6' and python_version not in '3.0, 3.1, 3.2, 3.3'",
+            "version": "==2.4.7"
+        },
+        "pytest": {
+            "hashes": [
+                "sha256:50bcad0a0b9c5a72c8e4e7c9855a3ad496ca6a881a3641b4260605450772c54b",
+                "sha256:91ef2131a9bd6be8f76f1f08eac5c5317221d6ad1e143ae03894b862e8976890"
+            ],
+            "index": "pypi",
+            "version": "==6.2.4"
+        },
+        "pytest-cov": {
+            "hashes": [
+                "sha256:261bb9e47e65bd099c89c3edf92972865210c36813f80ede5277dceb77a4a62a",
+                "sha256:261ceeb8c227b726249b376b8526b600f38667ee314f910353fa318caa01f4d7"
+            ],
+            "index": "pypi",
+            "version": "==2.12.1"
+        },
+        "toml": {
+            "hashes": [
+                "sha256:806143ae5bfb6a3c6e736a764057db0e6a0e05e338b5630894a5f779cabb4f9b",
+                "sha256:b3bda1d108d5dd99f4a20d24d9c348e91c4db7ab1b749200bded2f839ccbe68f"
+            ],
+            "markers": "python_version >= '2.6' and python_version not in '3.0, 3.1, 3.2, 3.3'",
+            "version": "==0.10.2"
+        }
+    }
+}
diff --git a/README.md b/README.md
index 247aba2..0f46b8b 100644
--- a/README.md
+++ b/README.md
@@ -5,7 +5,7 @@ Link do Curso [python Pro](https://plataforma.dev.pro.br/)
 [![Updates](https://pyup.io/repos/github/charlesnoamlael/charles_libpythonpro/shield.svg)](https://pyup.io/repos/github/charlesnoamlael/charles_libpythonpro/)
 [![Python 3](https://pyup.io/repos/github/charlesnoamlael/charles_libpythonpro/python-3-shield.svg)](https://pyup.io/repos/github/charlesnoamlael/charles_libpythonpro/)
 [![codecov](https://codecov.io/gh/charlesnoamlael/charles_libpythonpro/branch/charles_silva/graph/badge.svg?token=M95VIR4V6O)](https://codecov.io/gh/charlesnoamlael/charles_libpythonpro)
-suportada a versão 3 de python
+suportada a versão 3.7 de python
 
 para instalar:
 '''console
diff --git a/requirements-dev.txt b/requirements-dev.txt
deleted file mode 100644
index d27300e..0000000
--- a/requirements-dev.txt
+++ /dev/null
@@ -1,19 +0,0 @@
-flake8==3.9.2
-pyflakes==2.3.1
-mccabe==0.6.1
-pycodestyle==2.7.0
-requests==2.26.0
-
-# Deps do pytestt
-pytest==6.2.4
-py==1.8.2
-pyparsing==2.0.2
-atomicwrites==1.0
-pluggy<1.0.0a1,>=0.12
-attrs==19.2.0
-atomicwrites==1.0
--r requirements.txt
-
-# Coverage
-coverage==5.2.1
-pytest-cov==2.12.1
diff --git a/requirements.txt b/requirements.txt
deleted file mode 100644
index a2cd42a..0000000
--- a/requirements.txt
+++ /dev/null
@@ -1,14 +0,0 @@
-backports.entry-points-selectable==1.1.0
-certifi==2021.5.30
-charset-normalizer==2.0.3
-distlib==0.3.2
-filelock==3.0.12
-idna==3.2
-mccabe==0.6.1
-platformdirs==2.0.2
-pycodestyle==2.7.0
-requests==2.26.0
-six==1.16.0
-urllib3==1.26.6
-
-