Add saharaclient to global requirements

The python-saharaclient 0.6.0 release is a fully renamed version of ex.
savanna client with backward compat for both python bindings and cli,
so, we're planning to switch external projects requirements to the
saharaclient package imports and sahara cli command usage and then remove
python-savannaclient from the global requirements.

Change-Id: I97ea6560580931452c8739e4f6961412c873dac1
Removed openstacksdk from projects.txt

For now. Eventually it will be re-added, but right now the coordination
costs are higher than the value derived when we aren't even incubating.

Change-Id: I617c24cf02fe83c1fdf0a5e6b90a92851626890c
Merge "Add saharaclient to global requirements"
Merge "Removed openstacksdk from projects.txt"