OR-687 rename /core/notification/* files to be more consistent
OR-687 create a pubsub module for usernotification. It subscribe proper topics and create usernotification
OR-687 the usernotification pubsub handles community:membership:invite and community:membership:request
OR-687 create the addUserNotification method
OR-687 remove addUserNotification and fix tests due to merge problems
Merge pull request #502 in OR/rse from ~SLEMAISTRE/rse:OR-687 to master

* commit '75beab19c80a10b31868bdef4dec3bdf6b29ab01':
  OR-687 remove addUserNotification and fix tests due to merge problems
  OR-687 create the addUserNotification method
  OR-687 the usernotification pubsub handles community:membership:invite and community:membership:request
  OR-687 create a pubsub module for usernotification. It subscribe proper topics and create usernotification
  OR-687 rename /core/notification/* files to be more consistent
OR-687 fix tests
Merge pull request #512 in OR/rse from ~SLEMAISTRE/rse:OR-687 to master

* commit '5396ee20942a6b461c58e1523e4f4a696d1ab725':
  OR-687 fix tests