fix(package): update react-router-dom to version 5.1.2

Closes #132

Author: greenkeeper[bot]

package.json

@@ -133,7 +133,7 @@
     "react-hot-loader": "^4.0.0",
     "react-redux": "^5.0.7",
     "react-router": "^4.1.2",
-    "react-router-dom": "^4.1.2",
+    "react-router-dom": "^5.1.2",
     "react-router-redux": "^5.0.0-alpha.9",
     "redux": "^3.7.2",
     "redux-observable": "^0.19.0",