Gets the version from googleads/common.py.

  We can't import this directly because new users would get ImportErrors on our
  third party dependencies.

  Returns:
    The version of the library.

def GetVersion():
  """Gets the version from googleads/common.py.

  We can't import this directly because new users would get ImportErrors on our
  third party dependencies.

  Returns:
    The version of the library.
  """
  with open(os.path.join('googleads', 'common.py')) as versions_file:
    source = versions_file.read()
  return re.search('\\nVERSION = \'(.*?)\'', source).group(1)