Develop

[Michi03]

This PR introduces multiple major changes:

• The class structure has been reworked to more accurately fit the Moodle Modules
• The amount of retrieved data has been increased, now logging:
  • Forum posts
  • Post replies
  • Quiz attempts
  • Assignment submissions
  • View Events
• An authentication token has been added to every xAPI statement to identify the student
• The data proxy now starts a thread after a POST has been sent by the owner of the Moodle token
  • This thread automatically retrieves new activities every minute
  • The courses for which activities are retrieved can either be configured through the service properties file, or through the Moodle token access rights
• Also the docker start script was updated to connect to the blockchain of a las2peer network