Naive mirroring implementation
keys and secrets
Added config entry for source_index
Reworked source_lookup, storing json/ancestry/etc locally, removed decorator (obsolete)
Tags are mutable, they shouldn't be stored on mirrors
Added tags caching support (with TTL)
pep8 fix
Tags cache ttl expressed in seconds, small bugfixes, minor improvements
Reimplemented cleaned up mirror decorator
Applied source_lookup decorator on relevant methods
Added tags lookup decorator (and caching logic). Cleanup.
Enable OAuth 2.0 when using Google Cloud Storage as a Storage for
docker-registry.
rm self.
add oauth2 option to the config, merge both gcs flavors together.
Disable pyflake unused import warning
bugfixes
Update README.md
Adapt test Dockerfile to the new registry image
Merge pull request #274 from gregwebs/patch-2

Update README.md
Merge pull request #275 from mzdaniel/dockertest

Adapt test Dockerfile to the new registry image