Moved role constraints into model and removed edit deployment

(cherry picked from commit 720d202415b39aa622e9401113664727d14d5c3c)
Merge pull request #79 from vuntz/release/roxy/master

Moved role constraints into model and removed edit deployment
Removed the single assignment block from constraints
Merge pull request #80 from tboerger/feature/roxy/fix-constraints

Removed the single assignment block from constraints