Version Check on Invocation

[tobru]

Context

I observed that users are many times running an outdated version of Commodore. We should add a check on invocation which checks if the installed version of Commodore is up-to-date. This check should be configurable, so that one can choose that this check shouldn't be done (e.g. --disable-version-check) and it should be non-blocking, should the check not succeed fast enough.

It could compare the version with https://github.com/projectsyn/commodore/releases/latest, this automatically redirects to the latest version (the location header of the response, could be a HEAD).

Alternatives

Users running outdated versions of Commodore.

[mhutter]

Alternative proposal

Instead of connecting to GitHub on each invocation, document the version used to generate the catalog in the catalog itself.

If the current catalog was generated using a more recent version than is currently in use, emmit the warning (or abort or whatever).

Source: I've seen other tools (bundler, yarn) do this to generate their lockfiles.

Edit: Using an outdated version is, in my opinion, not an issue per se. Running an outdated version against a catalog that was compiled using a more recent version on the other hand is.