message: fix(hapi-engine): make server.ts compliant with typedef tslint rule
  Related to:
diff: @@ -9,7 +9,7 @@ import { readFileSync, existsSync } from 'fs';
  import { AppServerModule } from './src/<%= stripTsExtension(main) %>';
  // The Hapi server is exported so that it can be used by serverless functions.
  -export async function app() {
  +export async function app(): Promise<void> {
  const port = process.env.PORT || <%= serverPort %>;
  const distFolder = join(process.cwd(), '<%= browserDistDirectory %>');
  const server = new Server({
  