docs tests fail with multiformat codec errors

[andrewxhill]

https://github.com/textileio/docs/runs/1615334821?check_suite_focus=true#step:4:221

i've repeated this locally too.

@carsonfarmer is this one you've seen? known fix?

[carsonfarmer]

I haven't seen this one myself yet, but I know what's causing it. This is due to the new multiformats lib. I suspect its because we aren't locking in a version for that one, and since its pretty new we can't really trust the semver bumps there. I'll actually look into removing it completely. It still seems too unstable right now.

[carsonfarmer]

textileio/js-textile#793