Update ceph version in ceph testsuite config file

We don't want to fail every time the version changes, and wait for a fix
in the config file that is in git.
Properly set radosgw node in ceph test suite config file
Create a second backend for cinder to allow multi-backend testing

We create a local backend; that way we're sure it'll be available.
Merge pull request #85 from vuntz/ceph-testsuite-changes

Update for ceph testsuite changes
Makefile: run `apt-get update` before installing packages

Sometimes travis builds fail, because apt local index are outdated.
Merge pull request #91 from freyes/travis-apt-get-update

Makefile: run `apt-get update` before installing packages
Merge pull request #86 from vuntz/cinder-multibackend

Create a second backend for cinder to allow multi-backend testing
mkcloud: Add adminvcpus parameter

When running multiple nodes on limited hardware it's useful to set the
number of vcpus on the admin node independent from the other nodes.