fuel_upgrade: install few openstack releases

In Fuel 5.1 we will ship two openstack releases:

* 2014.1.1-5.1
* 2014.1.1-5.0.1

and we need to install them both. Since now it's possible to do.

Depends on a set of patches related to blueprint build-articats:

    https://review.openstack.org/#/q/project:stackforge/fuel-main+topic:bp/build-artifacts,n,z

Implements blueprint upgrade-to-5-1

Change-Id: I151534202de0aaac1bb7ae333a44b0b31b172b3b
Merge "fuel_upgrade: install few openstack releases"