autopep8 is an automated code formatting tool for python,
it does not know everything, also not super fast,
but it is faster than I can manually reformat the code.
tools/format.sh will call the formatting,
the tox will check did you called it.
Also adding a tox -eautopep8 way to use it.
autopep8 formats the lines in one way,
where tempest used a another way it was changed.
Change-Id: I6d51b14a5a5b87761071d0927fca23ba1651aa41
40fcb9ba28