Now one can use Rally for benchmarking OpenStack clouds that are using
LDAP, AD or any other read only keystone backend where you are not able
to create any users.
To do this one can specify "users" section in ExistingCloud plugin
input file.
Rally will use these "users" to generate load instead of creating new.
As well if you specify both "users" section in deployment input file
and "users" context it will use temporary created by Rally users.
Restructurize samples/deployments directory:
- Deploying OpenStack clouds with Rally is not popular functionallity
so hide all samples deeper.
- Some fixes in readme.rst
- Add new sample for existing cloud with predefined users
Change-Id: If3d31960ee317e0770abceacc62b3acf0947d269
