Merge pull request #78 from martinRenou/jlab2

Add support for Jupyterlab 2

Author: martinRenou

package.json

@@ -43,7 +43,7 @@
     "watch:nbextension": "webpack --watch"
   },
   "dependencies": {
-    "@jupyter-widgets/base": "^2.0.1",
+    "@jupyter-widgets/base": "^2.0.1 || ^3",
     "lodash": ">=4.17.13"
   },
   "devDependencies": {