Introduce Guru Meditation Reports into Nova

This commit integrates functionality from the
`openstack.common.report` module into Nova.
This enables Nova services to receive SIGUSR1
and print a Guru Meditation Report to stderr.
The required modules were added to
'openstack-common.conf' as well.

Change-Id: I224a426dad084f0e738069207ffbffe7f7935a17
Implements: blueprint guru-meditation-report
Re-Sync oslo-incubator fixtures

Syncing to add fixture.logging
(I7a4ab4f181634ed5b92ce88e9ed1d976ecb633a7) which will be enabled for
unit tests in a subsequent patch.

Commits Include:
 782fc83 Fixture to reraise exceptions raised during logging
 c178e56 Add basic Python 3 tests
 f6a97ac Enhance config fixture to support registering options
 b9d2ee4 Cleanup config fixture docstrings
 b8a191b Add 'new' parameter to mock.Patch and mock.PatchObject classes
 45658e2 Fix violations of H302:import only modules
 6fa29ae Trivial: Make vertical white space after license header
 consistent
 12bcdb7 Remove vim header
 3970d46 Fix typos in oslo
 371fa42 Move LockFixture into a fixtures module

Change-Id: I87e9e51610f3d00e92755c4f40aa295e60e440fb
Use oslo-common's logging fixture

Make the unit tests raise an exception when there is a logging
formatting issue. Related to oslo BP
logging-handleerror-raise-exception

Change-Id: Id4aa4277c387f1b67db4209d467c570b3c630f29
Merge "Introduce Guru Meditation Reports into Nova"
Merge "Re-Sync oslo-incubator fixtures"
Merge "Use oslo-common's logging fixture"