Implemented SaveEvent
Implemented FeedPostEvent
Implemented HelpfulMarkGivenEvent
Implemented LogCommentEvent
Implemented user data models:
 * OsbideUser
 * School
 * Course
 * CourseMembership
 * CourseRole
 * Assignment
 * Gender
 * ProfileImage
 * SystemRole
 * UserScore
Implemented SubmitEvent
Implemented EventLog and needed classes:
 * EventLog
 * EventLogData
 * EventLogSuscription