Upgrade dependencies for Node v12

Author: karlhorky

package.json

@@ -16,7 +16,7 @@
     "react-markdown": "^4.0.6",
     "react-router": "^4.3.1",
     "react-router-dom": "^4.3.1",
-    "react-scripts": "^2.1.5",
+    "react-scripts": "^3.0.1",
     "styled-components": "^4.1.3"
   },
   "scripts": {