Add pykmip

Add PyKMIP library, which is required to support KMIP as a secret
store within Barbican. Support for KMIP within Barbican has been
under active development -- see the "Support KMIP" blueprint at
  https://blueprints.launchpad.net/barbican/+spec/support-kmip
as well as the following change requests
  https://review.openstack.org/#/c/91107/
  https://review.openstack.org/#/c/101582/
  https://review.openstack.org/#/c/117539/
that implement this feature as an optional backend (i.e., "secret
store") for Barbican.

Change-Id: I315f9206dfc07fb2c4e342f6bd8b78c4079e6a5b
Merge "Add pykmip"
Revert "Exclude testtools 1.4.0"

This reverts commit b673b16ac572719cd8552c9cd05448409b628b28.

Change-Id: I0a142b3cbafa2af8b85a2f766c661ce3b69812b0