Annonymous users can not create groups.
Finished scenario: user is not inside the group.
Finished invite people to group feature.
Merge branch 'master' into invite_user_to_group
Implemented invitation functionality
Merge pull request #4 from henriquecf/invite_user_to_group

Invite user to group
Fixed scenario flickering.
Implemented restriction to groups user participates in invoices
Merge branch master