Use process substitution to redirect to tee
In some cases, when the daemon launched by a test panics and quits, the
cleanup code would end with an error when trying to kill it by its pid.
In those cases the whole suite will end up waiting for the daemon that
we start in .integration-daemon-start to finish and we end up waiting 2
hours for the CI to cancel after a timeout.
Using process substitution makes the integration tests quit.
Signed-off-by: Djordje Lukic <djordje.lukic@docker.com>