Implemented a Mocked version of the Registry server
Fixed mocked registry
Mocked registry: Added X-Docker-Size when fetching the layer
Disabled test server in the tests
registry: Fixed a bug where token and cookie info wouldn't be sent when using LookupRemoteImage(). Fixed a bug where no error would be reported when getting a non-200 status code in GetRemoteImageLayer()
Mock registry: Fixed a bug where the index validation path would return a 200 status code instead of the expected 204
New registry unit tests remade from scratch, using the mock registry
gofmt
Mock access logs don't show up in non-debug mode