Updated openstack/openstack
Project: openstack-dev/devstack  7610f0d8759b7a82d7a05ec8aa7c3a8d1b3c0e57
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add libxslt1-dev to tempest required files

tempest actually needs a pretty new lxml, which means it's
going to build it from source. To do that it needs libxslt1-dev
to compile. We should be good and let devstack do this out of
the box so it works on minimal environments.

Change-Id: Ia527905c1c15fb8c6793f0ce543ad05e25a88179
(cherry picked from commit db54311552d6c1efad7d9958a539848b3aeea775)