Unbind version of pyzmq

Currently pyzmq supports 2 branches with some API differences:
2.* - legacy branch
14.* - current branch

Due to historic reasons we bind pyzmq to an old API version.
In devstack we install latest version of pyzmq and not 2.* branch.
Cause of this I don't see any reason for us to bind pyzmq to such an old version.

Updating to latest version of pyzmq will allow us to implement zmq
driver in oslo.messaging that won't depend on eventlet and will be Py3
compatible.

Change-Id: I009e61303c01324de29ec78202621f50420d4d7f
Update to python-neutronclient 2.3.6

Nova needs python-neutronclient >= 2.3.6
for the new MacAddressInUseClient exception.

Change-Id: Id1b82f27ae09503ba3f4f92e5fa77f28b76d1580
Related-Bug: #1347778
Update python-swiftclient to >=2.2.0 for Heat

The generate_temp_url function in version 2.2.0 of python-swiftclient is
needed for the SwiftSignal resource in Heat:
https://review.openstack.org/#/c/96947/

Change-Id: I393a08fef09377ca2e41e5961849d6dd44514f8a
Bump keystoneclient to 0.10

Bump global requirements to the latest version of keystoneclient.

There are changes in the most recent version that are required to 
handle v3 authentication from keystonemiddleware, as well as 
updates to how clients consume the keystoneclient session objects.

Change-Id: I2998e790562c02693f95d885aab272a948c31822
Merge "Update to python-neutronclient 2.3.6"
Merge "Bump keystoneclient to 0.10"
Merge "Update python-swiftclient to >=2.2.0 for Heat"
Merge "Unbind version of pyzmq"