remove erb js file, fix typo in map.css, precompile assets

DO NOT MERGE. :warning: 

@MappingKat I found the syntax error that was blowing up the pipeline (see `app/assets/stylesheets/map.css`).  I also removed the .js.erb file that was conflicting with the non js version.  A couple problems remain though:

- the frontend is calling a hardcoded 'localhost:5555', which doesn't work on prod
- the css hardcoded in `application.html.erb` won't work on prod.  We'll have to include it in the pipeline.

Let's pair on Monday! :racehorse: