Add caching support to catalog

We will now cache the results of the catalog for 60s and not hit the database at all if cached

test/registry/protocol_v2.py

@@ -390,7 +390,7 @@ class V2Protocol(RegistryProtocol):
     return results
 
   def catalog(self, session, page_size=2, credentials=None, options=None, expected_failure=None,
-              namespace=None, repo_name=None):
+              namespace=None, repo_name=None, bearer_token=None):
     options = options or ProtocolOptions()
     scopes = options.scopes or []
 
@@ -409,6 +409,11 @@ class V2Protocol(RegistryProtocol):
         'Authorization': 'Bearer ' + token,
       }
 
+    if bearer_token is not None:
+      headers = {
+        'Authorization': 'Bearer ' + bearer_token,
+      }
+
     results = []
     url = '/v2/_catalog'
     params = {}