This test runs most of the time fine in CI. But, if run alone
locally, will fail consistently because the default `acl.conf` has a
catch-all `{allow, all}` clause. Probably another suite that runs
before this in CI unloads that and everything seems fine.
mongodb-erlang uses a special fork:
https://github.com/comtihon/poolboy.git
(which has overflow_ttl feature added).
However, it references `{branch, "master}`
should be `{ref, "9c06a9a"}` (2021-04-07).
By accident, We have always been using the upstream fork due to
eredis_cluster's dependency getting resolved earlier.
Here we pin 1.5.2 to avoid surprises in the future.
emqx_moduels for enterprise is refactored as a lib/plugin
in order to avoid merge conflicts, we make sure they can
co-exist in the same branch, because lib-opensource is compiled
in opensource project and lib-enterprise (to be added) is
compiled in enterprise project