Warn or fail CLI commands against incompatible server versions

We haven't yet upgraded to the 2020 Release (planning on doing that in roughly a month) and i'm currently working on automating our infrastructure deployment. As part of that i need to create ApiKeys in the release pipeline.
Initially i was looking for a "Seq Powershell Management Module" and only found the C# API so i was about to write my own tool before i remembered seqcli.

I went and downloaded, without a thought, the newest version from the release page and got to work and it seemed to work, except that it didn't create any Properties. After checking and playing with fiddler i found that it sent the Properties but not in the way Seq expects them, due to #135. At that point I've noticed that the versioning scheme of seqcli appears to match the Seq versioning scheme and that probably means that there's no backcompat and the seqcli version must match the Seq server version, but there's no mention in the readme / release page nor a warning in the cli that the versions must match or you might run into incompatibilities.

A version check in the seqcli could avoid some headache for future users 😉

Review the seqcli command-line behavior and the README/release page for how client and server versions are currently presented. Determine how incompatible server versions should be detected and whether the CLI should warn or fail, then verify that incompatible combinations produce the documented behavior.