For testing reasons it's typically very useful to have a second non
admin user to cross check that it can't do a thing to the first
user. It was useful enough we always created it with tempest (though
we didn't always use it).
This makes devstack always create an alt_demo user, which is available
in occ as devstack-alt. This will help us unwind some of the keystone
v3 breaks with functional tests using keystone cli to build this
second user.
Change-Id: Iaaf02469180563e2d8c413fee0ee66ada2296cfa
c67d22e2ed