Update tests that return something other than pass for success

As of commit 3044839456249f6f70b9642a60ad9be3dfb6056c tests that
return something other than the prescribed success atom 'pass' to
indicate success result in test failure. Change tests that return the
atom 'ok' or some other value to instead return 'pass' to indicate
success.
Merge branch 'refactor/change-ok-test-returns'