made test_format.py un-executable, so that nosetests runs it.

 Also fixed pep8 issues that this uncovered.
all skip_* fct are used to skip tests. You shouldn't use them in other file. I think this is the cause of the problem. It is better to have a warning in travis or install it then raising skip test in file that aren't tests. I think this is why the format tester fail. I try to load the module but fail due to this error.