Version 1.6.1 - adds support for Backups for Cloud Databases.
Merge branch 'master' into working
handle empty bodied response

Sometimes the response body doesn't contain anything, handle this error
condition by retrying, and remaining within the constraints of the
timeout.
Merge branch 'working' of github.com:rackspace/pyrax into working
Fixed a bug in parsing message and claim IDs
Merge branch 'working' of github.com:rackspace/pyrax into working
Added docs for the host parameter when creating usres. GitHub #229
Added the claim_id parameter to message deletion calls.
Fixed issue with the create_user() failing without a host. GitHub #246
pep8 cleanup
Removed requirement for client ID for non-message queue requests. GitHub #244
Added parameter explanation to the Block Storage doc. GitHub #248
Added missing 'host' parameter. GitHub #246
Added support for wheel distribution
Removed files accidentally included in the repo.
Added support for ServiceNet queues. GitHub #240
Manually merged PR from ephur. GitHub #237
Fixed missing file spec. GitHub #245
Fixed some issues with test_utils.py
Updated version and release notes.