Port HP 3PAR driver to Python 3

Port HP 3PAR driver to Python 3

* Use oslo_serialization.base64.encode_as_text() to get Unicode on
  Python 3.
* Replace sys.maxint with sys.maxsize, sys.maxint was removed in
  Python 3.
* test_hpe3par: use list(set()) to get FCWWNs is the right order. On
  Python 3, the hash function is randomized by default.
* test_hpe3par: fix client getWsApiVersion() to return a valid
  version. Before, the comparison between mock.Mock and int raised a
  TypeError.
* hpe_3par_common: set version to 3.0.2
* hpe_3par_iscsi: set version to 3.0.1
* tox.ini: add test_hpe3par to Python 3.4

Partial-Implements: blueprint cinder-python3
Change-Id: I2bed171c0db93b8ea83127a69a63c3bb2317b10b