Added nova compute

Also configured horizon to display hypervisors.

roles/nova-compute/tasks/main.yml

@@ -0,0 +1,24 @@
+# Build and install a docker image for nova-controller.
+---
+- name: install service file.
+  template:
+    src: templates/nova-compute.service
+    dest: /etc/systemd/system/nova-compute.service
+    mode: 644
+    owner: root
+    group: root
+
+- command: systemctl daemon-reload
+
+- apt:
+    name: '{{ item }}'
+  with_items:
+      - kvm
+      - libvirt0
+      - libvirt-bin
+      - qemu
+
+- name: make sure service is started
+  systemd:
+    name: nova-compute.service
+    state: restarted