Currently, the couchbase optional peer dependency is semver range ^2.1.6 (ie: 2.x).

This semver range communicates to me:

We've tested the couchbase module at version 2.1.6, any newer than that, at your own risk.

Another way to read it is:

We know this to work from 2.1.6 up until a version we do not mention, or up until 2.Infinity.Infinity.

Since I read it the first way (and I know this to be the case with at least the couchbase module), I'm scared to install anything newer unless I go through the full changelog of the couchbase module, and check which APIs of it are being used by MAGE and how. That's a lot of work that we can't expect normal users of MAGE to do.

I on the other hand have gone through the entire couchbase diff between version 2.1.6 and (latest) 2.3.3 and can confirm that it should be absolutely safe to use 2.3.3 as far as MAGE is concerned.

How people use couchbase directly is not in our hands, so we can't be too restrictive on versions (we can't bump the minimum required version too aggressively), but it's very important that we communicate our certainty about peer dependency versions working well with MAGE.

For that reason I propose that we change our semver range policy to include both the lowest known version and the highest known version known to work with MAGE.

So in the case of couchbase, I suggest we would mark it as >=2.1.6 <=2.3.3.

Thoughts?