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: I149d8e4e8fac6aa5c496b8f186aa0afb28bf81c2
Closes-Bug: #1269090
(cherry picked from commit 52a7b6ecbad11c08dcd77a6fcd8bfef6a20324a9)
Merge "Run neutron-debug with admin tenant in neutron-adv-test" into stable/havana