heroku config:set BUILDPACK_URL=https://github.com/getpelican/heroku-buildpack-pelican
To allow this buildpack to redirect any secondary domains, you can define the environmental variable 'PELICAN_SITEURL'.
heroku config:set PELICAN_SITEURL=http://getpelican.com
Now any requests to http://pelican.herokuapp.com
or http://www.getpelican.com
will redirect to the SITEURL