fix(package): update react to version 16.3.0

Closes #38

Author: greenkeeper[bot]

package.json

@@ -7,7 +7,7 @@
     "serve": "^5.0.1"
   },
   "dependencies": {
-    "react": "^15.4.0",
+    "react": "^16.3.0",
     "react-dom": "^15.4.0",
     "react-router": "^4.0.0",
     "react-router-dom": "^4.0.0"