Add sidekiq to the Procfile.
Store archive after submission has been saved.

* The submission ID is required to determine the correct
  directory to store the file.
Render all files in a submission.
Can comment on individual files.
Style inline comments.
Avoid displaying duplicate inline comments.
Remove un-used code.

* The archive extraction was moved to a worker.
Merge pull request #20 from atsheehan/file_comments

File comments