Automate the process for compatibility test

[jadolg]

Rocket.Chat has new versions almost every month and patches get deployed all the time.
It makes sense to automate the process of getting all versions and updating the test matrix.
Versions are collected from https://docs.rocket.chat/docs/version-durability and are being rotated including the new ones and discarding the ones that fall out of support.
Ideas:

1. Automatically pulling the versions with every CI run. (No maintenance burden but needs to be done in a clever way so we always know what's being tested)
2. Create a PR periodically with the new versions. (Has a maintenance overhead but we have proven record of when things changed)