Package version updates don't quite follow semantic versioning for 0.X releases

[yorickpeterse]

The semantic versioning specification states the following:

Major version zero (0.y.z) is for initial development. Anything MAY change at any time. The public API SHOULD NOT be considered stable.

We currently don't follow this when handling package version updates, as we only constrain the updates the mayor version number. This means that if a package specifies it needs dependency A with a minimum version of 0.2.3, and version 0.3.0 is released, inko pkg update will bump the version requirement to 0.3.0, instead of using whatever the latest version of 0.2.X is.

The question is whether we actually want the semver behaviour, or stick with what we currently do. The reason is that for example many Rust libraries perpetually stay at version 0.X even though they are backwards compatible, simply because authors don't want to commit to an officially stable API.

I'm personally not sure just yet as to what approach is the best here.