Merge pull request #222 from consideRatio/jlab21

geojson: support JupyterLab 2.1.0

Author: Steven Silvester

packages/geojson-extension/package.json

@@ -34,7 +34,7 @@
     "watch": "tsc -w"
   },
   "dependencies": {
-    "@jupyterlab/apputils": "~2.0.0",
+    "@jupyterlab/apputils": "^2.0.0",
     "@jupyterlab/rendermime-interfaces": "^2.0.0",
     "@lumino/messaging": "^1.2.2",
     "@lumino/widgets": "^1.11.0",