Change effective on 31 July 2017
The default version of Apache Tomcat used by the Heroku CLI Deploy plugin to run Java WAR files has been upgrade to version 8.5.15. You can customize the version by adding the
--webapp-runner option to the
heroku deploy:war command and using any of the available Webapp Runner version, which correspond to Tomcat versions. For more information on Tomcat Webapp Runner, see the project documentation. For more information on deploying WAR files to Heroku see the Dev Center guide.