Deploy the Spinner with the Tile

[johnsonj]

Push the Spinner cf app as part of the tile. Re-use the service account used by the nozzle. This may require adding a GOOGLE_CREDENTIALS_JSON to the manifest and plumbing it through to the stackdriver client (see root_service_account_json, client creation as an example)

Surface the configuration options (with friendly name/description/sane default):

• SPINNER_COUNT
• SPINNER_WAIT

Open questions:

• Do we need to enable/disable it or just assume users want it?
• Should we need to deploy multiple instances?

/cc @hustons @sahilm @GarimaSharma (+tom)