This patch adds provider driver support to the Octavia v2 API, starting
with the load balancer API.
This patch also creates a provider driver for Octavia, initially fully
implementing the load balancer methods.
Follow on patches will implement the remain parts of the API.
Change-Id: Ia15280827799d1800c23ed76d2af0e3596b9d2f7
Story: 1655768
Task: 5165
7b2621fe29