Codebase is now flake8 compliant

.travis.yml

@@ -5,10 +5,7 @@ python:
 install:
     - pip install flake8
 script:
-    # stop the build if there are Python syntax errors or undefined names
-    - flake8 . --count --select=E901,E999,F821,F822,F823 --statistics
-    # exit-zero treats all errors as warnings.
-    - flake8 . --count --exit-zero --max-complexity=10 --max-line-length=92 --statistics
+    - flake8 . --count --max-complexity=10 --max-line-length=92 --statistics
 notifications:
     on_success: change
     on_failure: change  # `always` will be the setting once code changes slow down