Allow heroku deploy template to be auto-detected.

README.md

@@ -61,7 +61,7 @@ Now compatible with all Android devices as old as version 4.0.x - [download here
 
 
 ## Heroku
-Host your own Rocket.Chat server for **FREE** with [One-Click Deploy](https://heroku.com/deploy?template=https://github.com/RocketChat/Rocket.Chat/tree/master)
+Host your own Rocket.Chat server for **FREE** with [One-Click Deploy](https://heroku.com/deploy)
 
 [![Deploy](https://www.herokucdn.com/deploy/button.png)](https://heroku.com/deploy?template=https://github.com/RocketChat/Rocket.Chat/tree/develop)