Test properly if registry is a mirror
fix flask raise ValueError when mirroring
Merge pull request #453 from dotcloud/invalid-mirror-mode-fix

Fix invalid mirror mode
Merge pull request #456 from lilinux/master

fix flask raise ValueError when mirroring
Fix typo: should be lowercase T for True
Merge pull request #457 from activars/patch-1

Fix typo: should be lowercase T for True