Summary:
The Maestro team just released a new version of maestro which dies in our CI
This change pins the version to something we know it's working, so we can decide when to move to the next version
## Changelog
[Internal] - Pin Maestro version
Reviewed By: cortinico
Differential Revision: D60380466
fbshipit-source-id: af842b7922736cc08300ac3bceef2d6110bcd913