Stop using intersphinx

Remove intersphinx from the docs build as it triggers network calls that
occasionally fail, and we don't really use intersphinx (links other
sphinx documents out on the internet)

This also removes the requirement for internet access during docs build.

This causes docs jobs to fail because we error out on warnings.

Change-Id: I71e941e2a639641a662a163c682eb86d51de42fb
Related-Bug: #1368910
Adjust authentication.rst doc to reference "identity_uri"

The "auth_port", "auth_host", and "auth_protocol" variables were
deprecated in favour of a single "identity_uri" variable.

* Adjust authentication.rst doc to reference "identity_uri"

Change-Id: I48de53f21b8d767b276858ed274066015d765f0e
Closes-Bug: #1361613
Merge "Stop using intersphinx"
Merge "Adjust authentication.rst doc to reference "identity_uri""