fix: package.json to reduce vulnerabilities

The following vulnerabilities are fixed with an upgrade:
- https://snyk.io/vuln/npm:react-dom:20180802

package.json

@@ -65,7 +65,7 @@
     "moment": "^2.18.1",
     "mousetrap": "^1.6.1",
     "react": "^15.3.2",
-    "react-dom": "^15.3.2",
+    "react-dom": "^16.0.1",
     "react-hammerjs": "^0.5.0",
     "read-chunk": "^2.0.0",
     "strong-data-uri": "^1.0.4",