Always register api.domain with the router

* api.domain will always reach the cloud controller.
* Any existing prefixes will also be registered so they will work too.
* Manifests that use ccng will continue to work with both ccng.domain and
api.domain with no changes.
backfill basic VCAP::UaaUtil tests
uaa: backfill caching test for VCAP::UaaUtil
consolidate asymmetric key refresh in UaaVerificationKey
use real rsa key to test VCAP::UaaUtil
raise TokenExpired when token has expired
refactor auth token validation specs
Add test for register_routes
tests: integration: removed unnecessary WebMock.allow_new_connect!
turned UaaUtil into UaaTokenDecoder class
uaa: added integration test for auth tokens
uaa: scope uaa config portion for token decoder
Merge pull request #34 from cloudfoundry/api_host_default

Always register api.domain with the router
removed redis dependency
integration tests: refactor common functionality
improve multi_response_nats_request spec

make it less time sensitive