Config cleaning, switch to gunicorn config file instead of cli args
Merge branch 'master' of github.com:dotcloud/docker-registry
- Added test_s3.py file which tests the S3Storage library using moto.
 * The methods stream_write and stream_read are not supported by moto yet
 * The s3_access_key and s3_secret_key must be lower case in order to perform the tests.