Improve test output for clarity

[Delano]

Define what these run-time args mean and the effect they have on the output.

  opts.on('-q', '--quiet', 'Run in quiet mode') { options[:quiet] = true }
  opts.on('-v', '--verbose', 'Run in verbose mode') { options[:noisy] = true }
  opts.on('-f', '--fails', 'Show only failing tryouts') { options[:fails] = true }
  opts.on('-D', '--debug', 'Run in debug mode') { Tryouts.debug = true }