Fix the order of enabling devstack plugin

The order of enabling devstack plugin is important if project
has dependency of other projects.
Magnum has some dependency of projects, so this patch fixes
the order of enabling plugin.

Change-Id: I733e061fab4ed40fd00bfb017d9c2835c49f6a8f

doc/source/dev/quickstart.rst

@@ -119,7 +119,7 @@ Kilo, and heat must be enabled by yourself)::
     ADMIN_PASSWORD=password
     # magnum requires the following to be set correctly
     PUBLIC_INTERFACE=eth1
-    enable_plugin magnum https://git.openstack.org/openstack/magnum
+
     # Enable barbican service and use it to store TLS certificates
     # For details http://docs.openstack.org/developer/magnum/dev/tls.html
     enable_plugin barbican https://git.openstack.org/openstack/barbican
@@ -127,6 +127,9 @@ Kilo, and heat must be enabled by yourself)::
     enable_plugin neutron-lbaas https://git.openstack.org/openstack/neutron-lbaas
     enable_plugin octavia https://git.openstack.org/openstack/octavia
 
+    # Enable magnum plugin after dependent plugins
+    enable_plugin magnum https://git.openstack.org/openstack/magnum
+
     # Disable LBaaS(v1) service
     disable_service q-lbaas
     # Enable LBaaS(v2) services

magnum/tests/contrib/gate_hook.sh

@@ -20,7 +20,6 @@ special=$2
 
 export PROJECTS="openstack/barbican $PROJECTS"
 export DEVSTACK_LOCAL_CONFIG="enable_plugin heat git://git.openstack.org/openstack/heat"
-export DEVSTACK_LOCAL_CONFIG+=$'\n'"enable_plugin magnum git://git.openstack.org/openstack/magnum"
 export DEVSTACK_LOCAL_CONFIG+=$'\n'"enable_plugin ceilometer git://git.openstack.org/openstack/ceilometer"
 
 if [ "${coe}${special}" != "k8s-ironic" ]; then
@@ -83,4 +82,7 @@ else
     export DEVSTACK_LOCAL_CONFIG+=$'\n'"MAGNUM_IMAGE_NAME='fedora-atomic-f23-dib'"
 fi
 
+# Enable magnum plugin in the last step
+export DEVSTACK_LOCAL_CONFIG+=$'\n'"enable_plugin magnum git://git.openstack.org/openstack/magnum"
+
 $BASE/new/devstack-gate/devstack-vm-gate.sh