Sync fixture module from oslo

Changes pulled:

  [f4a4855] Consolidate the use of stubs
  [6111131] Make openstack.common.fixture.config Py3 compliant

Due to the changes to the stub use, a couple of tests (the ones in
test_shelve) needed to have some cleanups removed that depended on some
stubs still being in place and not others. The normal DB cleanup
procedure handles this correctly, so the cleanups were superfluous
anyway.

The test in test_manager was split in two to avoid it resetting its
stubs halfway through. It was testing two separate scenarios anyway, so
it's the correct thing to do regardless.

I'll submit a patch later to get rid of all the superfluous VerifyAll
and UnsetStubs calls across the entire test suite, but for now, let's
just get the gate working again, shall we?

Fixes bug #1239898

Change-Id: I3aa4dfc0261a861e5eaa570849329292d64236ed
remove unused network module from certificates api extension

Closes-Bug: 1240823

Change-Id: I5d37a7bc9ac0ede079feebc4121d3585de44d8bd
Merge "Sync fixture module from oslo"
xenapi: post install scriptlet to rpm

A freshly installed XenServer requires some modifications in order to be
able to run OpenStack. Nova contains an rpm specification to create a
package with the dom0 plugins, however installing the rpm is not enough.
Some more actions need to be taken:
 - create /images, link to a directory within the local SR
 - setup an ssh keypair, and authenticate it with the host
This change adds a post script to the nova plugins rpm spec file, so
by installing the rpm on a XenServer, it is ready to run OpenStack, no
further manual actions needed.

Change-Id: Id57e3a3ab2782550468c6aa4c01059ceb7cc81ab