Refactor plugin_manager.py for PEP8 adherence
Refactor backends/base.py for PEP8 adherence
Merge pull request #165 from zoni/pep8

PEP8
Update config-template.py

KEEPALIVE typo
Added python version check to the plugin manager
removed unused import
calm down lthe log verbosity for the tests
put the compatibility for the test plugin
Update .travis.yml