instance method parse!

# File railties/lib/commands/plugin.rb, line 659
    def parse!(args)
      options.parse!(args)
      count = 0
      args.each do |uri|
        if Repositories.instance.remove(uri)
          count += 1
          puts "removed: #{uri.ljust(50)}"
        else
          puts "failed: #{uri.ljust(50)}"
        end
      end
      Repositories.instance.save
      puts "Removed #{count} repositories."
    end