I'm able to get get past that and get the app deployed, but then I just get application error trying to launch it. Then I went and looked at the build log. I'm not sure its even doing anything:

-----> Fetching custom git buildpack... done -----> Null app detected -----> Nothing to do. -----> Discovering process types Procfile declares types -> web -----> Compressing... done, 33.1MB -----> Launching... done, v5