fix(package): update react-scripts to version 3.4.0

Closes #18

Author: greenkeeper[bot]

package.json

@@ -17,7 +17,7 @@
     "react-apollo": "^2.2.4",
     "react-dom": "^16.6.0",
     "react-router-dom": "^4.3.1",
-    "react-scripts": "3.1.0",
+    "react-scripts": "3.4.0",
     "subscriptions-transport-ws": "^0.9.15"
   },
   "scripts": {