Add PEP8 check

Add pep8 check in TravisCI and fix the pylint bug.

Signed-off-by: Hao Liu <hliu@redhat.com>
Merge pull request #2 from Hao-Liu/add_pep8

Add PEP8 check
Output statistics when break test with Ctrl+C

Signed-off-by: Hao Liu <hliu@redhat.com>