fix(package): update react-router to version 5.1.0

Closes #114

Author: greenkeeper[bot]

package.json

@@ -169,7 +169,7 @@
     "react": "^16.0.0",
     "react-dom": "^16.0.0",
     "react-redux": "^5.0.1",
-    "react-router": "^4.1.1",
+    "react-router": "^5.1.0",
     "react-router-dom": "^4.1.1",
     "react-router-redux": "^5.0.0-alpha.6",
     "redux": "^3.6.0",