Move to github actions and update for moodle 3.11

Abort and delete processes whose courses got deleted

Travis: Update for Moodle 3.10

Fix Delay View for MySQL

Change postgresql to 9.6

Delete backup files in file area after copying

This changes the default of just proceeding a course. However, I can not
think of a scenario were this would make sense.

The delete course step should override the process_waiting_course
function in order to process waiting courses correctly.

Test for Moodle 38 Release