Rename run_tests.sh to wrap_nosetests.sh

run_tests.sh has a different purpose in CM than
run_tests.sh in Nova, which causes confusion. Renamed the file
to better reflect its true intent.

Change-Id: I206fdeab8b052f85e1485164f019979ebbff4fbb
Merge "Rename run_tests.sh to wrap_nosetests.sh"