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

On Sat, Dec 06, 2014 at 06:04:49PM -0800, Aaron Meurer wrote:
>    This is the rule I'm strongly -1 to enforcing (this is a line
>    continuation).

Then please explain what exactly we should support in PEP8 and
what shouldn't?