Generate random keystone users

Change-Id: I8dbd07b10d29b43d1c35fa76bcaa0f0efb32beda
Related-Prod: PROD-29868
diff --git a/opencontrail/compute/single.yml b/opencontrail/compute/single.yml
index 72dda61..c6b1aca 100644
--- a/opencontrail/compute/single.yml
+++ b/opencontrail/compute/single.yml
@@ -28,7 +28,7 @@
       network:
         engine: keystone
         host: ${_param:control_address}
-        user: neutron
+        user: ${_param:keystone_neutron_username}
         password: ${_param:keystone_neutron_password}
         tenant: service
   neutron:
@@ -38,7 +38,7 @@
         engine: keystone
         host: ${_param:control_address}
         port: 35357
-        user: neutron
+        user: ${_param:keystone_neutron_username}
         password: ${_param:keystone_neutron_password}
         tenant: service