Bump the mapml-leaflet-plugin dependency in bower.json to 0.4.0

Author: prushforth

bower.json

@@ -33,7 +33,7 @@
     "tests"
   ],
   "dependencies": {
-    "mapml-leaflet-plugin": "Maps4HTML/MapML-Leaflet-Plugin#^0.3.0",
+    "mapml-leaflet-plugin": "Maps4HTML/MapML-Leaflet-Plugin#^0.4.0",
     "polymer": "^1.5.0"
   },
   "devDependencies": {