FYI, 19beta1 server working fine for us

Hi. We've been bitten in the past, so we're trying to be proactive
testing the betas to surface issues early. We've setup a 19beta1
cluster on Linux, and we've been able to run all our unit tests
against it (which are a mix of low-level true unit-tests, and very
high-level integration tests, FWIW), using our current 18.3 libpq
client, from both Windows and Linux clients. Just an FYI. Thanks for
the good work. --DD