Fix heat role create error

https://review.openstack.org/#/c/76036/ changed the user creat commands,
missed the argument to --user

Change-Id: Iaf10ef80a2fb0227dd66a314e7ec253dfb4dc4fe
Fix Neutron enabled check

The pending revision to is_service_enabled() requires is_neutron_enabled() to
be declared before it is indirectly called in lib/neutron.  Also
exercises/volume.sh needs to source lib/neutron to do the check in ping_check().

Change-Id: I1c458aaa787ffb98c945aefc3afa80c6861a405f
Merge branch 'set-conf-dir' into dt-test