Changes format and indents for pep8

This is changes in code formating and indentation
to comply with pep8 standard.

It follows current setting in tox.ini for pep8 (flake8).

I skipped errors like:
* F821 undefined name
* H302 import only modules

This pull request is first to prepare tuskar for CI (TravisCI)
and for better developer experience as @jistr noted at #47