To-do:

  * Add tests for unit.rb.
  * Add documentation for command-line selection of tests using unit.rb.
  * #assert_nothing_raised does not filter the stack trace of the exception.
  * Add accessors for failures and errors to TestResult?
  * Add a summarizing TestRunner.
  * Automatic running should not happen if the exit was caused by an error.
  * Allow the selection of multiple test orderings.
  * Clean up grammar and spelling issues in the docs.
  * Add .rpk generation to packaging process.
  * If a failure is nested in a helper method call, provide some indicator of where in the test method it occurred.
  * Fix RUnit compatibility not filtering assert.rb properly.
  * Fix $IGNORECASE bug.
  * Add the ability to keep going if an assertion fails.
  * Extract the test collector hiding in unit.rb.
  * Add a file system test collector.
  * Review documentation.
  * Optimize.
  * Allow the addition of "always run" setup [ruby-talk:60980].
  * Verify that the GTK::TestRunner is actually working.
