This test substitutes for the spec test here:

https://github.com/mongodb/specifications/blob/master/source/initial-dns-seedlist-discovery/tests/uri-with-auth.json

Since our Mongo Orchestration configurations set username and password to
"bob:pwd123", it's easier to test with that username and password than the
"auser:apass" user in the official spec test. See CDRIVER-2868.
