Disable deploy some releases

In order to force customers moving to new releases or for technical
reasons we want to forbid deploying some releases. For this reason we
need to introduce a special field in the Relases model.

Please note, the field has no affect in experimental mode.

Change-Id: Iaf315d291ce9f18ad52b15c030be193d0d5ea6f9
Closes-Bug: #1368100
Merge "Disable deploy some releases"