Update to pydocstyle

Author: groteworld

.travis.yml

@@ -4,8 +4,8 @@ python:
 # command to install dependencies
 install:
   - pip install flake8
-  - pip install pep257
+  - pip install pydocstyle
 # command to run tests
 script:
   - flake8 . --max-line-length=120
-  - pep257 . --ignore=D202
+  - pydocstyle . --add-ignore=D202