added react-tooltip.

package.json

@@ -48,6 +48,7 @@
     "react-mosaic-component": "^1.1.1",
     "react-numeric-input": "^2.2.3",
     "react-select": "^1.2.1",
+    "react-tooltip": "^3.6.1",
     "selfsigned": "^1.10.3",
     "signals": "^1.0.0",
     "three": "github:mozillareality/three.js#hubs-editor/dev",