CI: use pytest-flake8

.flake8

@@ -0,0 +1,3 @@
+[flake8]
+select = F
+ignore = E,W,C,F401,F841,F541

.travis.yml

@@ -34,7 +34,7 @@ script:
   - helm version --client
   - chartpress --version
   - chartpress --help
-  - pytest --verbose --flakes
+  - pytest --verbose --flake8
 
 jobs:
   include:

README.md

@@ -233,5 +233,5 @@ pip install  -e .
 pip install -r dev-requirements.txt
 
 # run tests
-pytest --verbose --flakes --exitfirst
+pytest --verbose --flake8 --exitfirst
 ```

dev-requirements.txt

@@ -1,4 +1,4 @@
 bump2version
 gitpython
 pytest
-pytest-flakes
+pytest-flake8

tests/README.md

@@ -2,16 +2,15 @@
 
 These tests are [pytest](https://docs.pytest.org) tests.
 
-
 ```bash
-pytest -vx --flakes
+pytest -vx --flake8
 
 # -v / --verbose:
 #   allows you to see the names etc of individual tests etc.
 # -x / --exitfirst:
 #   to stop running tests of first error
-# --flakes:
-#   use pyflakes to add some static code analysis tests
+# --flake8:
+#   use pytest-flake8 to add some static code analysis tests
 # -k:
 #   only run tests which match the given substring
 ```
@@ -23,7 +22,7 @@ pytest -vx --flakes
 - [pytest](https://docs.pytest.org)
   - Fixture: [capfd](https://docs.pytest.org/en/latest/reference.html#_pytest.capture.capfd)
   - Fixture: [monkeypatching](https://docs.pytest.org/en/latest/capfd.html)
-- [pytest-flakes](https://github.com/fschulze/pytest-flakes) and
+- [pytest-flake8](https://github.com/fschulze/pytest-flakes) and
   [pyflakes](https://github.com/PyCQA/pyflakes) for passive code check tests
   added to the other pytest tests when using the `--flakes` flag with `pytest`.
 - [GitPython](https://gitpython.readthedocs.io/en/stable/)