Moved role constraints into model and removed edit deployment

(cherry picked from commit 89abbe5183cd1635fd35005473dae69548f3657b)
Merge pull request #80 from vuntz/release/roxy/master

Moved role constraints into model and removed edit deployment
Removed the single assignment block from constraints
Merge pull request #81 from tboerger/feature/roxy/fix-constraints

Removed the single assignment block from constraints