Drop lab variables polyfill (#400)

Author: SylvainCorlay

js/package-lock.json

@@ -24,7 +24,7 @@
     "webpack": "^3.5.5"
   },
   "dependencies": {
-    "@jupyter-widgets/base": "^1.1 || ^2.0",
+    "@jupyter-widgets/base": "^2.0",
     "leaflet": "^1.3.0",
     "leaflet-draw": "^1.0.4",
     "leaflet.markercluster": "^1.2.0",

js/package.json

@@ -45,8 +45,6 @@ require('leaflet.markercluster/dist/MarkerCluster.Default.css');
 require('leaflet-measure/dist/leaflet-measure.css');
 require('leaflet-fullscreen/dist/leaflet.fullscreen.css');
 require('./jupyter-leaflet.css');
-require('./theme/materialcolors.css');
-require('./theme/labvariables.css');
 
 // Forcibly load the marker icon images to be in the bundle.
 require('leaflet/dist/images/marker-shadow.png');