Add a check target.
Add a check target.

Just developer convenience - I'm used to autotools 'make check'
environments.

Change-Id: Idf5bb882f798d22d4513756b5273d4ae19caa5c0

bcrochet/tripleo-heat-templates,rdo-management/tripleo-heat-templates,openstack/tripleo-heat-templates,redhat-openstack/tripleo-heat-templates,dprince/tripleo-heat-templates,wyg3958/tripleo-heat-templates,trozet/tripleo-heat-templates,openstack/tripleo-heat-templates,trozet/opnfv-tht,dprince/tripleo-heat-templates,rdo-management/tripleo-heat-templates,trozet/tripleo-heat-templates,redhat-openstack/tripleo-heat-templates,bcrochet/tripleo-heat-templates,bcrochet/tripleo-heat-templates,trozet/opnfv-tht,trozet/opnfv-tht,wyg3958/tripleo-heat-templates