Convert trove to plugin

Also adds an is_trove_enabled() function to match
https://review.openstack.org/69497 changes for is_service_enabled().

Change-Id: Ic0408ff6d9816aec8a3506931470470342a5dcd7
diff --git a/lib/trove b/lib/trove
index 8e817f5..9c91024 100644
--- a/lib/trove
+++ b/lib/trove
@@ -38,6 +38,16 @@
     TROVE_BIN_DIR=$(get_python_exec_prefix)
 fi
 
+# Functions
+# ---------
+
+# Test if any Trove services are enabled
+# is_trove_enabled
+function is_trove_enabled {
+    [[ ,${ENABLED_SERVICES} =~ ,"tr-" ]] && return 0
+    return 1
+}
+
 # setup_trove_logging() - Adds logging configuration to conf files
 function setup_trove_logging() {
     local CONF=$1