logging.warn() is deprecated in Python 3 [1]. While it is not in the short-term list of priorities for Packstack, it does not hurt to use logging.warning [2], which is forward-compatible. Closes-Bug: 1508442 [1]https://docs.python.org/3/library/logging.html#logging.warning [2]https://docs.python.org/2/library/logging.html#logging.warning Change-Id: I7c13513720280415350a83fd6ed0636af476a20e