Ticket 49085 - Make a short topology fixture alias
Description: Modify create_test.py, so it will insert "topo" import alias
instead of long topology names like "topology_m1h1c1".
With it we have more readable code - 'topo.ms["master1"]'.
https://fedorahosted.org/389/ticket/49085
Reviewed by: mreynolds (Thanks!)