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

Which rule enforces this? This is one I don't like because if you are trying to stay at the proper line length and have longer option names or named parameters in a call statement, it gets hard (or impossible) to keep the wrapping flush left with the opening paren.