hs_service/helper_functions test seems unreliable on slow systems
Hi! I've seen this test failure a few times on Travis:
hs_service/helper_functions: [forking] FAIL src/test/test_hs_service.c:837: assert(ip->time_to_expire OP_GE now + INTRO_POINT_LIFETIME_MIN_SECONDS): 1537602275 vs 1537602297 [helper_functions FAILED]
It seems to happen intermittently, so I think it might be one of those things where a slow-running machine fails the test because of the unexpected passage of time.
Is it possible to mock time here?