Invalidate the blob store descriptor caches when content is removed from from

the proxy.  Also, switch to reference in the scheduler API.

Signed-off-by: Richard Scothern <richard.scothern@gmail.com>

docs/proxy/proxymanifeststore_test.go

@@ -119,6 +119,7 @@ func newManifestStoreTestEnv(t *testing.T, name, tag string) *manifestStoreTestE
 			localManifests:  localManifests,
 			remoteManifests: truthManifests,
 			scheduler:       s,
+			repositoryName:  nameRef,
 		},
 	}
 }