add support for pushing and running on heroku

package.json

@@ -24,9 +24,10 @@
     "webpack-dev-server": "3.1.14"
   },
   "scripts": {
-    "start": "webpack --mode development",
-    "dev": "webpack-dev-server --mode development --open",
-    "build": "webpack --mode production"
+    "start": "node server.js",
+    "dev": "webpack-dev-server --mode development",
+    "build": "webpack --mode production",
+    "heroku-postbuild": "yarn run build"
   },
   "dependencies": {
     "@babel/runtime": "7.2.0",

server.js

@@ -0,0 +1,13 @@
+const express = require("express");
+const path = require("path");
+
+const app = express();
+
+app.use(express.static(path.join(__dirname, "build")));
+
+app.get("*", (req, res) => {
+  res.sendFile(path.join(__dirname, "build", "index.html"));
+});
+
+const port = process.env.PORT || 4444;
+app.listen(port, () => console.log(`server running on port ${port}`));