Merge branch '2.1.x'

Author: snicoll

spring-boot-project/spring-boot-docs/src/main/asciidoc/deployment.adoc

@@ -225,7 +225,9 @@ deployments is to `git push` the code to production, as shown in the following e
 	 * [new branch]      master -> master
 ----
 
-Your application should now be up and running on Heroku.
+Your application should now be up and running on Heroku. For more details, refer to
+https://devcenter.heroku.com/articles/deploying-spring-boot-apps-to-heroku[Deploying
+Spring Boot Applications to Heroku].