Add Constraints support

Adding constraints support to libraries is slightly more complex than
services as the libraries themselves are listed in upper-constraints.txt
which leads to errors that you can't install a specific version and a
constrained version.

This change adds constraints support by also adding a helper script to
edit the constraints to remove designate-tempest-plugin.

Change-Id: I2f9c14a84089047bff5f6a77bbd234fda175d229
2 files changed