Add oslo.vmware into test-requirements

Add oslo.vmware into test-requirements

run_tests.sh is currently broken due to the commit that made
installing oslo.vmware optional: e67adc385ce6997249fbf70e9402264f758fc6f4

There are test cases that require oslo.vmware and the change made in the
commit for tox doesn't cover the case where run_tests.sh is used.  Without
including oslo.vmware in the test-requirements file there are a number of
test cases that fail without the library installed.

This patch resolves the issue by move oslo.vmware over to the
test-requirements file.

Change-Id: I2ffd21a23552e39bdb220c4aaa0c5e372c52f7ce