Ok, now I get it. I guess the problem occurred only in the  'templates/supervisord.conf.erb'. Is that right?

From http://stackoverflow.com/questions/4127274/rails-erb-best-practices-vs-vs
> What is the recommended use of ERb in Rails when it comes to <% %> (evaluate Ruby code), <% -%> (evaluate Ruby code, suppress the trailing newline) and <%- -%> (evaluate Ruby code, suppress the trailing newline and leading space)? It seems like <%- -%> would make the output HTML look nicest, but <% %> seems to be mostly what I see.

This is correct for this file, but it's a issue with ' templates/supervisord.conf.erb'.
I would fix this issue in a different commit and revoke this changes.