Create a new extension to the proxy, which will allow networks to be
extended across clouds.
Additionally, provide lots of documentation for this new feature.
Change-Id: I9088e3509f71fb363ddc7f504cbb96f94932cc1e
This introduces preliminary support for extensions.
Extensions are registered to routes, and if the
request matches the registered route they will be
called to handle the request and the response.
The interface is still not finalized and will
progress as more extensions with their different
requirements are added.
Also included dependency on oslo_serialization for
loading the json response. Follow up patch will
change all instances of json.loads to
jsonutils.loads
Change-Id: I9c573ce1d4ebe85c07c8ff219f384e3c6c67b39a