Updated openstack/openstack
Project: openstack-dev/devstack  2d947c47c6d9edd2fbb50db13d40cefb19a20db5
null
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