This patchset tunes the Drydock MAAS request factory to:
a) Implement retries for requests toward MAAS_URL/api/2.0/
b) Bumps the request timeout slightly
In addition, restricts threaded actions towards nodes to
using the same MAAS client, effectively rate limiting calls
to the MAAS api.
Change-Id: I2e66105ae332adaed62c9c3bc8cddc63e1f7bf23