The URL of the video is not stored in the same attribute of the response
if WebTorrent is enabled or not.
It caused a bug when trying to play a video which do not use WebTorrent.
Also create a "quality" job to run pylint automatically on merge
requests. The contributing guidelines are updated with this information
and the remaining pylint violations were fixed in the code.
See merge request StCyr/plugin.video.peertube!11 for more information
Libtorrent is required to play videos but its installation is still
manual so now a message is displayed when libtorrent could not be
imported instead of having a "service could not start" error at Kodi
startup.
The message contains a link to a page which explains how to install
libtorrent. It will be displayed when:
* the add-on starts
* the user selects a video to play (including when called externally)
Other additions:
* Create a kodi_utils module to centralize some calls to the Kodi API
* Add license information in the header of the files
* Ignore some files in Git (python cache and Mac OS system file)