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.
Ilya Averyanov