Fix forgotten package

- extras is now included in packages declaration
- alphabetically ordered now to avoid more churn

Author: Olivier Gambier

setup.py

@@ -47,11 +47,13 @@
 # Explicit packages list to avoid setup_tools funkyness
 packages = ['docker_registry',
             'docker_registry.drivers',
-            'docker_registry.server',
+            'docker_registry.extensions',
+            'docker_registry.extras',
             'docker_registry.lib',
-            'docker_registry.storage',
             'docker_registry.lib.index',
-            'docker_registry.extensions']
+            'docker_registry.server',
+            'docker_registry.storage',
+            ]
 
 namespaces = ['docker_registry', 'docker_registry.drivers']