Change effective on 06 August 2014
There are three methods to include a settings file in a Heroku project:
Put a file named
settings.xml in the root directory of the project.
MAVEN_SETTINGS_PATH config variable to the location of a settings file relative to the root directory.
MAVEN_SETTINGS_URL config variable to the URL of a settings file.
For more information see the Devcenter article on using Maven settings files with Heroku.