Send integration output to /dev/null
Send integration output to /dev/null

It all gets queued up after the test report, and looks pretty much like
gibberish, so it should definitely be removed.

Signed-off-by: mulhern <7b51bcf507bcd7afb72bf8663752c0ddbeb517f6@redhat.com>

stratis-storage/stratis-cli,stratis-storage/stratis-cli