code: def _version_string():
      
      platform_system = platform.system()
      if platform_system == 'Linux':
          os_name, os_version, _ = platform.dist()
      else:
          os_name = platform_system
          os_version = platform.version()
      python_version = platform.python_version()
      return 'trytravis %s (%s %s, python %s)' % (__version__,
                                                  os_name.lower(),
                                                  os_version,
                                                  python_version)
docs: Gets the output for `trytravis --version`.