Add oslo.concurrency and oslo.middleware

Install the oslo.concurrency and oslo.middleware libraries from source so
the gate tests are run against master.

Change-Id: I194fc160127ab8b4b7d0086586d8ba7f92c67076
Add oslo.log

Install the oslo.log library from source so the gate tests
are run against master.

Change-Id: Id2925ce733773d8189ecc0d24b0384c44fad7b72
Merge "Add oslo.concurrency and oslo.middleware"
Merge "Add oslo.log"
Merge branch 'master' of https://github.com/openstack-dev/devstack