Move ironic to plugin

Also adds an is_ironic_enabled() function to prepare for an upcoming
change in is_service_enabled().

Change-Id: I6e6e0e8b70221e231785ab27e9b5d4836933ac4c
diff --git a/lib/ironic b/lib/ironic
index afbc3e0..afb7c23 100644
--- a/lib/ironic
+++ b/lib/ironic
@@ -46,6 +46,13 @@
 # Functions
 # ---------
 
+# Test if any Ironic services are enabled
+# is_ironic_enabled
+function is_ironic_enabled {
+    [[ ,${ENABLED_SERVICES} =~ ,"ir-" ]] && return 0
+    return 1
+}
+
 # install_ironic() - Collect source and prepare
 function install_ironic() {
     git_clone $IRONIC_REPO $IRONIC_DIR $IRONIC_BRANCH