Add test for non accepted invitation
Post OauthSettings instead of ServiceProvider
Display correct fields in the form
Refactored notice in flash to BaseController
Clean invitations table after test
Call to ServiceRegistry when posting oauthsettings

For now implemented only as a Stub.
Move mock to loplevel package
Boyscout formatting
Add sample json for get to serviceregistry
Added convertion between Stoker to ServiceRegistry