Add .cjs extension to calls to force CommonJS mode in Node v12+

[rdmurphy]

Fixes #6.

@Qix- You were correct! Adding .cjs to all calls and writes of _do_hook and _detect_package_hooks didn't bother Node v10 (which just runs them as CommonJS as always), and it successfully makes both Node v12 and Node v14 aware.

I was just testing it out by uninstalling and reinstalling then triggering the commit hook in the repo I discovered this in, so might benefit from another person poking on it.

[Qix-]

Great! - sorry for the delay, I'll publish this right now. Thanks again for all the work :)

[Qix-]

Nevermind, no I won't 😅 it appears my publish access has been dropped, cc @leo.

[leerob]

I can make sure this gets released! Thank you 😄

[Qix-]

@leerob That's not quite what I asked. I used to have permissions to manage this package as I was the original author and the person still trusted to release this. It's not common in the Node community to completely strip someone's authorship from code they wrote - generally frowned upon 🙃 It's especially not what I expected from ZEIT.

Can you be more specific or clear about what kind of role I play with this package these days? It'd be beneficial to Vercel, myself, and most importantly the users of this package to be clear, as the changes made on #8 make it seem like I'm no longer wanted around here.

If someone wants to take over maintainership of this package, that's fine, let's just make that clear to the existing maintainers 😉

[leerob]

Context: I've only been at Vercel for 8 months, so I was not here in the ZEIT days.

I'm happy to re-add you as a maintainer of the package. I'm only jumping in here to help with releasing, as it will need to be transferred over the Vercel NPM organization, and we're not looking to open up NPM publishing permission outside of our organization (for security reasons).

Sorry for the confusion here and for folks not getting back to you in a timely manner. Leo/G are never really on GitHub anymore as they're pretty busy 😄