Create a rackspace provider for openstack-reddwarf

https://issues.apache.org/jira/browse/JCLOUDS-103

Rackspace US:
mvn -Plive clean install "-Dtest.rackspace-us.identity=[redacted]" "-Dtest.rackspace-us.credential=[redacted api key]"
Rackspace UK:
mvn -Plive clean install "-Dtest.rackspace-uk.identity=[redacted]" "-Dtest.rackspace-uk.credential=[redacted api key]"