Remove unused iso8601

AuthProtocol doesn't have an _iso8601, so the test shouldn't set it.

Change-Id: Ia4773be0fe9e17b96700e6aa56f663e706af94a8
Update oslo-incubator and switch to oslo.{utils,serialization}

Update to commit 9ce1d96fb2e075fcd5b9ddbee728c0ee49d2be56

Change-Id: I27e20f76fb0f4b858230b2c36e6ff960e1ec9d09
Clean up the middleware docs

Used code blocks when possible, and a minimal amount of
highlighting keywords.

Change-Id: Ie1dad50cc44afc6ce841e87f2ee9de3149e72117
Merge "Clean up the middleware docs"
Merge "Remove unused iso8601"