Moved role constraints into model and removed edit deployment

(cherry picked from commit 6af9728f3ea5cba675f3c29de4f3bb59a132ac94)
Merge pull request #154 from vuntz/release/roxy/master

Moved role constraints into model and removed edit deployment
Removed the single assignment block from constraints
Merge pull request #155 from tboerger/feature/roxy/fix-constraints

Removed the single assignment block from constraints