Mxs 1140 keepalived (#166)

add keepalived test

maxscale-system-test/nodes.h

@@ -64,6 +64,16 @@ public:
 
     char hostname[256][1024];
 
+    /**
+     * @brief stop_vm_command Command to suspend VM
+     */
+    char stop_vm_command[256][1024];
+    /**
+
+     * @brief start_vm_command Command to resume VM
+     */
+    char start_vm_command[256][1024];
+
     /**
      * @brief   User name to access backend nodes
      */