Restricting ChefSpec::Coverage to this cookbook

Change-Id: Ia3bde592e0cb7ff6f9b60ccac889792ce7bd52a6
Addresses: blueprint lint-and-unit-testing-for-havana
Make service_plugins configurable

So far, the service_plugins configuration setting of neutron server has
been used exclusivly for the loadbalancer plugin.  However, in different
usage contexts it can be used for more.  Therefore, this change makes
the service_plugins setting configurable.

This change deprecates node["openstack"]["network"]["neutron_loadbalancer"].
To use the loadbalancer as a service plugin, please add

  neutron.plugins.services.agent_loadbalancer.plugin.LoadBalancerPlugin

to node['openstack']['network']['service_plugins']

Change-Id: I6f1cf72f7bbb9625dbace778189f938841bfbe2b
Utilise ['openstack']['region'] from cookbook-openstack-common

- Set ['openstack']['network']['region'] to equal ['openstack']['region']
- Add test to override the endpoint region and confirm it is used

Change-Id: I68463f8cad7c424115ad75a39068c880ad3d3ef9
Addresses: blueprint uniform-region
Merge "Restricting ChefSpec::Coverage to this cookbook"
Merge "Utilise ['openstack']['region'] from cookbook-openstack-common"
Merge "Make service_plugins configurable"