Convert server to typescript

This was just a rename and one potential type conversion error.

Author: rylnd

test/server.js renamed to test/server.ts

@@ -17,12 +17,11 @@ app.use('/avatars', avatarsRoutes);
 const listen = (port) => {
   app.listen(port, function () {
     const { address } = this.address();
-    // eslint-disable-next-line no-console
     console.log(`[Adorable Avatars] Running at: http://${address}:${port}`.green);
   });
 };
 
-const port = process.env.PORT || 3002;
+const port = Number(process.env.PORT) || 3002;
 
 if (port > 3002) {
   listen(port);