harden tests

[nilsnolde]

currently we only test for a vroom-express failure it seems, meaning vroom is never actually called and issues like #61 can go unnoticed.

we definitely need to make that more robust and test for a 200 as well with the example2.json.

in fact, I just see that we actually do want to request for a 200, but curl doesn't fail unless called with --fail:

vroom-docker/tests/test.sh

Lines 31 to 32 in df2a620

	# tests that the service starts up alright
	do_request > /dev/null

easy fix, I'll that real quick.