old_contents: #!/usr/bin/env python3
  
  import trunc
  
  
  def test_version_number():
      package_version = trunc.__version__
      print("package version is {}".format(package_version))
      assert '0.0.1a1' == package_version
  
new_contents: #!/usr/bin/env python3
  
  import trunc
  
  
  def test_version_number():
      package_version = trunc.__version__
      print("package version is {}".format(package_version))
      assert package_version and isinstance(package_version, str)
  
subject: update test of version number