feat: Wait for initial compile (#39), fixes #38

* await

* return ready promise

Author: AlexandreBonaventure

lib/app.js

@@ -140,6 +140,7 @@ module.exports = (app, options) => {
       }
       ssr(req, res)
     })
+    return readyPromise
   } catch (e) {
     console.error(e)
   }

lib/server.js

@@ -5,10 +5,10 @@ exports.createServer = ({
   port,
   host,
 }) => {
-  return new Promise((resolve, reject) => {
+  return new Promise(async (resolve, reject) => {
     const app = express()
 
-    applyApp(app)
+    await applyApp(app)
 
     app.listen(port, host, err => {
       if (err) {