fix(package): update react-router-dom to version 5.1.1

Closes #11

Author: greenkeeper[bot]

package.json

@@ -16,7 +16,7 @@
     "react": "^16.6.0",
     "react-apollo": "^2.2.4",
     "react-dom": "^16.6.0",
-    "react-router-dom": "^4.3.1",
+    "react-router-dom": "^5.1.1",
     "react-scripts": "3.1.0",
     "subscriptions-transport-ws": "^0.9.15"
   },