Support UCA/Havana, Icehouse and Trusty in Ubuntu.

Needs VMS 2.8 or higher.
Yum repositories now expect a url to key.

The new yum cookbook (3.x series) got rid of the 'yum_key' resource in
favor of using a 'key' parameter which accepts a url (similar to
apt). This is unfortunately a backwards-compatibility breaking change,
but since we have no known centos users at the moment we're modifying
the cookbook to explictly depend on the new yum cookbook.
Bump version to 1.3.0.

This version has been tested against ubuntu precise and centos 6.4,
openstack versions grizzly and havana, with combinations of
nova-network and quantum/neutron based networking.
Merge pull request #17 from rmahmood/ucatrusty

Support UCA/Havana, Icehouse and Trusty in Ubuntu.