Add Google Cloud Functions API to catalog
Add Google Cloud Functions API to catalog

jskeet/gcloud-dotnet,jskeet/google-cloud-dotnet,jskeet/google-cloud-dotnet,jskeet/google-cloud-dotnet,jskeet/google-cloud-dotnet,googleapis/google-cloud-dotnet,jskeet/google-cloud-dotnet,googleapis/google-cloud-dotnet,googleapis/google-cloud-dotnet