Include PARK_HEAD_ON_PAUSE in Travis testing

.travis.yml

   - opt_set MOTHERBOARD BOARD_MINIRAMBO
   - build_marlin
   #
-  # Test FILAMENT_CHANGE_FEATURE and LCD_INFO_MENU
+  # Test FILAMENT_CHANGE_FEATURE, PARK_HEAD_ON_PAUSE, and LCD_INFO_MENU
   #
   - restore_configs
   - opt_enable ULTIMAKERCONTROLLER
-  - opt_enable_adv FILAMENT_CHANGE_FEATURE LCD_INFO_MENU
+  - opt_enable_adv FILAMENT_CHANGE_FEATURE PARK_HEAD_ON_PAUSE LCD_INFO_MENU
   - build_marlin
   #
   # Enable filament sensor