Add pep8 config, use pep8 in travis

also, fix E111-E113 errors:
E111 - indentation is not a multiple of four
E112 - expected an indented block
E113 - unexpected indentation

> I recently found out that pep8.py is constantly being updated; any project that uses it should probably select a specific version

That's why this pr is "on hold".  I don't like using master version, but right now there is no options.