travis/style: setup tests better in travis and some style fixes

Author: mishaschwartz

.travis.yml

@@ -3,9 +3,6 @@ python:
   - "3.6"
   - "3.7"
   - "3.8"
-# command to install dependencies
-install:
-  - pip install pytest
 # command to run tests
 script:
-  - pytest
+  - python setup.py test