Stop creating KeystoneAdmin KeystoneServiceAdmin sysadmin netadmin roles

These roles have absolutely no use anymore since quite some time. And
they were dropped from the sample data in Grizzly:
https://github.com/openstack/keystone/commit/d6f7cbc484868bdec3eeb9d4b0f45b10ce536e79
Merge pull request #84 from saschpe/release/pebbles/master-keystoneconf-grizzly

Rebase keystone.conf to Grizzly.
Merge pull request #89 from saschpe/release/pebbles/master-token-signing

 	Configurable cert locations for token signing
Merge pull request #90 from vuntz/drop-unneeded-roles

Stop creating KeystoneAdmin KeystoneServiceAdmin sysadmin netadmin roles
SSL support for native frontend