'system-wide-install' sounds slightly strange because when we specify
this option, we don't install anything. So it was decided to deprecate
this option in favor of 'system-wide' that is more suitable.
If we execute `rally verify start --help`, we will see the following
warning:
$ rally verify start --help
...
--system-wide Don't create a virtual env when installing Tempest;
use the local env instead of the Tempest virtual env
when running the tests. Take notice that all Tempest
requirements have to be already installed in the local
env!
--system-wide-install
DEPRECATED! Use --system-wide instead
...
Change-Id: I663c18cb85715d732bb9c5012e3e23ca10751d5a
6d1197368f