This is a patch to start work on re-writing the integration tests
using pytest syntax and several improvements, as proposed on the
upstream meeting, and summarized at https://etherpad.opendev.org/p/horizon-pytest
The new tests are to eventually replace the existing integration
tests. At the moment they don't run automatically, you have to explicitly run them using tox or pytest. When the new tests are complete, we will switch to them on the gate.
Change-Id: Iea38e4f9771ff3cae7ae8675863e9c488f3f6d8a
36536272ff