Add a fake cloud impl.
Update the service registry with unit tests.
Merge pull request #150 from brendandburns/tests

Add in service registry tests and a Fake Cloud impl.
Add IP look up if the Cloud Provider is not null
Add Instance info to the Cloud Provider interface
Add support for populating host ip address.
Merge pull request #161 from brendandburns/next

Add population of the host IP address when on GCE.
Add a PodCache that is responsible for caching pod information.
Not wired in yet.