Make output_path accessible via config

[Uelb]

What about being able to change the output dir, indeed, the coverage dir is often ignored in the git tree of projects I think.

[Uelb]

This is how I deal with that right now. To put it in the spec folder.

SimpleCov.start do
  require 'simplecov-badge'
  require 'simplecov-json'
  class SimpleCov::Formatter::BadgeFormatter
    def output_path
      File.expand_path("../", __FILE__)
    end
  end
end

[radubogdan]

I can work on this :)