Run neutron-debug with admin tenant in neutron-adv-test

Because neutron-debug create-probe needs admin role only, demo tenants
cannot create ports. neutron-debug is wrapped in order to run it only
with admin tenant.

Change-Id: Ib65e8639858c597345c6a5fdc0192b40f34a0300
Closes-Bug: #1269090
Merge "Run neutron-debug with admin tenant in neutron-adv-test"