sahara-* repos aren't part of integrated release

That means that sahara-ptl group should be able to release all sahara-*
projects (sahara-dashboard, sahara-image-elements and sahara-extra). The
separated acl file has been added for this projects.

Change-Id: I2780b7b9fa6a579b8dd92c4f79aa599882594eba
Merge "sahara-* repos aren't part of integrated release"