Go to root directory of the repo that contains index.html which dictates the main HTML page.
touch composer.json //run this to create a file called composer.json.
{} //add this inside composer.json
touch index.php //run this to create a file called index.php.
<?php include_once("index.html"); ?>  //add this inside index.php
it push heroku master //this will deploy the app-- check it out!