Add neutron-large-ops-testing job

Add neutron-large-ops-testing job to experimental queue.

This is a follow up to I98baec6e0890f6b10afbd9858ded933f59db9725 which
added a large-ops-testing job to the experimental queue. In addition to
checking if nova-networking works with the new large-ops value (175) we need
to check neutron.

Change-Id: I431eb47a5620e788b9ffe3faefbcab580b88a441
Merge "Add neutron-large-ops-testing job"