Use the oslo fixture module

The oslo fixture import has been imported
And the tests code have been updated to use this new module

Change-Id: I3454440770402c028f49a92c6728d7bbad0c9aa0
Harden version checking for boto

Simple string comparison is not effective for version checking.
Let's switch to using pkg_resources.parse_version and compare
the tuples. Per review feedback, enabling the code path for
2.13 as well. Originally we had handled this by excluding
2.13 from requirements. With this we should be able to removing
the exclusion for 2.13 from global requirements.

Change-Id: Ie047f7201d8e6a9a9641000d387c4312506f49b1
Closes-Bug: #1239220
Merge "Use the oslo fixture module"
Merge "Harden version checking for boto"
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