Fix invite static resend
Fix warnings in IntelliJ
Basic practical teacher administration
Fix the tests and checkstyle
Merge pull request #29 from florisverburg/feature_teacher

Feature teacher
Messages can be sent
Fixed checkstyle
Fix that invite messages don't depend on user
Merge pull request #30 from florisverburg/feature_messages

Send messages
First setup of the recommendation
mend
Made a first random recommendation
Added a basic and not completely functioning version of the recommendation algorithm