Separate lint and test builds

The pep8/pylint are now executed in separate builds.

Signed-off-by: Michal Čihař <michal@cihar.com>
Selenium tests should no longer fail

Signed-off-by: Michal Čihař <michal@cihar.com>
Document travis setup

Signed-off-by: Michal Čihař <michal@cihar.com>