Activity completion support, improved scoring and logging

[sbourget]

This patch resolves issue #22 and also partially implements #14.

It addresses the following:

Adds tracking of user scores. Uses AJAX to write the scores to the database.
Improves logging allowing teachers / admins to identify who has been using the module.
Implements the callbacks for the outline and complete reports now that we have data that can be viewed on the reports.
Implements course reset as now we have scores that can be cleared.
Implements a page for teachers etc to view all student scores.
Adds support for activity completion for both views and minimum score
Adds unit tests for the events
Fixes remaining travis issues (travis is now passing)

[xow]

@sbourget Is there any chance you'd be interested in continuing this work?

Scores are effected by GDPR as the users should be able to export and delete their scores

[sbourget]

Yes, I can work on implementing the Privacy API.
Is there anything else needed to allow this PR to be merged? (Other than fixing the version conflict?)

[sbourget]

@xow I just put together the GDPR support for this and updated the pull request as #43 (I had several conflicts attempting to update this PR, so it was easier to submit a new one.)

Let me know if there is anything else I can do to help move this issue along.

[xow]

Ah ok @sbourget should we close this one?

[sbourget]

Sure, lets close this one and hopefully finish this up in #43