[bundler] Better library support

[deivid-rodriguez]

Hello! 👋

Thanks so much for maintaining dependabot, I use it all the time :)

I just got this PR to my library: deivid-rodriguez/pry-byebug#295.

I would've expected dependabot to detect that it was only a development dependency update, and automerge it.

I think dependabot should be able to detect that it's creating a PR for a library (a criteria could be that there's a gemspec file in the root of the project), and in that case consider any update not touching the gemspec file as a development dependency update.

Thanks!

[jeffwidman]

Closing, as we aren't doing native automerge, although there is a workaround you can setup leveraging GitHub actions.

[deivid-rodriguez]

Hei @jeffwidman. My issue was not related to automerge per se, but about detection of development vs production dependencies in the Ruby ecosystem. Even if automerge is no longer a thing, this can still be used for things, for example: https://docs.github.com/en/code-security/dependabot/dependabot-version-updates/configuration-options-for-the-dependabot.yml-file#allow.

That said, I'm not sure whether this is still an issue. If it is, I'll make sure to reopen!