old_contents: #!/usr/bin/env python
  import sys
  import unittest
  
  from os.path import dirname, abspath
  
  import tests
  
  def runtests(*test_args):
      suite = unittest.TestLoader().loadTestsFromModule(tests)
      result = unittest.TextTestRunner(verbosity=2).run(suite)
      sys.exit(bool(result.failures))
  
  if __name__ == '__main__':
      runtests(*sys.argv[1:])
  
new_contents: #!/usr/bin/env python
  import sys
  import unittest
  
  from os.path import dirname, abspath
  
  import tests
  
  def runtests(*test_args):
      suite = unittest.TestLoader().loadTestsFromModule(tests)
      result = unittest.TextTestRunner(verbosity=2).run(suite)
      if result.failures:
          sys.exit(1)
      elif result.errors:
          sys.exit(2)
      sys.exit(0)
  
  if __name__ == '__main__':
      runtests(*sys.argv[1:])
  
subject: Return the proper exit codes in event of failure or error