[For Review Only] Facade for heroku grader to accept archive files and run them locally 

- **grader and specs**
- **rag/grade launch script, entry in autograder_subprocess, and Gemfile**

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- still have to switch to Logger
- suppressing a couple exceptions, like to get feedback on those
- also like to get feed back on rails_up_timeout: https://github.com/apelade/rag/blob/marcelo_heroku/lib/graders/rspec_grader/rails_intro_archive_grader.rb#L107