Log Message:
sysutils/py-kazoo: update to 2.4.0

Changes 2.4.0:

PYTHON SUPPORTED VERSIONS CHANGE: Please note that Kazoo no longer tests
on Python 2.6 or 3.3. Tested versions are 2.7, 3.4, 3.5, 3.6, and PyPy. The
multiple endpoint support for KazooClient may not work correctly on 2.6.

Bug Fixes
*   add missed parens to LockingQueue function call.
* **core:**  revert 305 SetWatches which caused RuntimeError

Features
*   pep8 all the thingsloses
*   drop Python 2.6/3.3 official support, add 3.5/3.6 testingloses
* **core:**
  *  allow multiple endpoints in KazooClient hosts arg
  *  use epoll when available to support fds > 1023
* **recipe:**  Add TreeCache recipe