Change effective on 08 August 2017
Heroku’s support for Java, Scala, Clojure, Groovy and JRuby applications now includes the option of using the Azul® Zulu® JDK versions 8u144 and 7u154. To use Zulu with your app, create a
system.properties file in the root directory of your application with the following contents:
Add this file to Git, and the official buildpacks will install the specified version of the JDK on the next deployment.