travis: Customized rules for pylint + pep8 checks

*  There's no need to pep8 check any unittests.
*  pylint ignore rules are different for unittests,
   dockertest modules, and test modules.
*  It's handy to have the full path to each file
   being checked, since esp. test class names
   can and do clash.

Signed-off-by: Chris Evich <cevich@redhat.com>