Fix custom virtualenv directory for tempest

Related to bug: 1370086
Shell environment is checked with low case,
but should be with upper case. See check in script
tools/with_env.sh.

Change-Id: I6b720c462b8a562e3276f9e64d723bc36fb5c842
Merge "Fix custom virtualenv directory for tempest"
Updated from global requirements

Change-Id: I0cd4932a576e5677217f2a6cc31b4e809079501f