Adjust integrated gate for neutron changes
Adjust integrated gate for neutron changes

neutron moved in I2cfa6030cb0826665d48d2c5e73f29401b6c1f4b some jobs
in-tree, adjust integrated-gate for this.

Also, add a description for the template.

Change-Id: I00c04c148663e6fcd1b42cd66efeb4177b763a84

openstack-infra/openstack-zuul-jobs,openstack-infra/openstack-zuul-jobs