Install ironic-ui from git source rather than a pip package

This patch changes the horizon ironic dashboard to be installed from
git sources like all of the other dashboards in an openstack-ansible
deployment.

Without this change the package installed from pypi is always the
latest released version and not aligned with the release
being deployed with openstack-ansible. This will potentially
cause the horizon service to fail to start if there is a severe
mismatch between horizon and ironic-ui.

Change-Id: I4dd03f3cd13878dafb621c70dd44a4fd0ff99ae3

defaults/main.yml

@@ -98,6 +98,10 @@ trove_dashboard_git_install_branch: "{{ horizon_git_track_branch }}"
 heat_dashboard_git_repo: https://opendev.org/openstack/heat-dashboard
 heat_dashboard_git_install_branch: "{{ horizon_git_track_branch }}"
 
+## The git source/branch for the Ironic UI plugin
+ironic_dashboard_git_repo: https://opendev.org/openstack/ironic-ui
+ironic_dashboard_git_install_branch: "{{ horizon_git_track_branch }}"
+
 ## The git source/branch for the Watcher UI plugin
 watcher_dashboard_git_repo: https://opendev.org/openstack/watcher-dashboard
 watcher_dashboard_git_install_branch: "{{ horizon_git_track_branch }}"
@@ -454,7 +458,7 @@ horizon_designate_optional_pip_packages:
 horizon_heat_optional_pip_packages:
   - "git+{{ heat_dashboard_git_repo }}@{{ heat_dashboard_git_install_branch }}#egg=heat_dashboard"
 horizon_ironic_optional_pip_packages:
-  - ironic-ui
+  - "git+{{ ironic_dashboard_git_repo }}@{{ ironic_dashboard_git_install_branch }}#egg=ironic-ui"
 horizon_magnum_optional_pip_packages:
   - "git+{{ magnum_dashboard_git_repo }}@{{ magnum_dashboard_git_install_branch }}#egg=magnum-ui"
 horizon_manila_optional_pip_packages: