Update deploying-heroku-mlab.md

_includes/parse-server/deploying-heroku-mlab.md

@@ -1,13 +1,20 @@
-## Deploying to Heroku and mLab
+## Deploying to Heroku and MongoDB Atlas
 
-Heroku and mLab provide an easy way to deploy Parse Server, especially if you're new to managing your own backend infrastructure.
+Heroku and MongoDB Atlas provide an easy way to deploy Parse Server, especially if you're new to managing your own backend infrastructure.
 
 Here are the steps:
 
 1. Create a repo for your Express app with the Parse Server middleware mounted (you can use our [sample project](https://github.com/parse-community/parse-server-example), or start your own).
 2. Create a Heroku account (if you don’t have one already) and use the Heroku Toolbelt to log in and prepare a new app in the same directory as your Express app. Take a look at Heroku's [Getting Started with Node.js guide](https://devcenter.heroku.com/articles/getting-started-with-nodejs#introduction) for more details.
-3. Use the mLab addon: `heroku addons:create mongolab:sandbox` (or, you can create a Mongo instance yourself, either directly with mLab or your own box)
-4. Use heroku config and note the URI provided by mLab under the var MONGOLAB_URI
+3. Set up your MongoDB database:
+    1. Sign up for a [MongoDB Atlas account](https://www.mongodb.com/cloud/atlas).
+    2. Create a `New Project`.
+    3. Open the page `Database Access` and create a new database user with username and password. Remember these user credentials, you will need them later to connect Parse Server to the database. As user privileges choose `Read and write to any database`, you can change these privileges later on and make them more restrictive according to your needs.
+    4. Open the page `Clusters` and create a new cluster.
+    5. On the cluster details page, click on the tab `Collections` and create a new database.
+    6. On the cluster details page, click on the tab `Command Line Tools`, click on `Connect Instructions` and choose `Connect your application`.
+    7. Copy the database connection string. Replace the placeholders in the connection string with the username and password of the user you created earlier and the database name.
+4. Use heroku config and note the URI provided by Atlas under the var MONGOLAB_URI
 5. Copy this URI and set it as a new config variable: `heroku config:set DATABASE_URI=mongodb://...`
 6. Deploy it: `git push heroku master`