Check python with flake8 instead of dib-lint

We check python files with dib-lint rather than flake8 which have
conflicting opinions. This means weve been (forcibly) writing non pep8
python.

Also fixing pep8 issues so tests pass.

Change-Id: Idc9db40334f6e15738a7802c06697270df68741c
Merge "Check python with flake8 instead of dib-lint"