Move esm to devDependencies

[DatGreekChick]

Launch Checklist

• briefly describe the changes in this PR
• write tests for all new functionality
• document any changes to public APIs
• post benchmark scores
• manually test the debug page
• tagged @mapbox/studio and/or @mapbox/maps-design if this PR includes style spec changes
• tagged @mapbox/gl-native if this PR includes shader changes or needs a native port

@ryanhamley @mourner @asheemmamoowala

I moved esm to devDependencies and ran yarn install to update the yarn.lock file.

Using yarn removed any errors with tests that I was having previously in #8513 due to npm - thanks for that! I saw the docs, but didn't realize it would have this type of impact.

CLOSES #8450

[ryanhamley]

Thanks for taking another crack at this @DatGreekChick! The change itself looks fine, but there shouldn't be large changes to the yarn.lock file just from moving esm to devDependencies. In fact, if I try it myself, I don't get any changes at all to yarn.lock. Can you make sure your forked version of the repo is up to date and that you're using a newer version of Yarn? Older versions of Yarn have a tendency to unnecessarily change the lock file. For reference, I'm on Yarn 1.17.3 in Node 8.11.4

[DatGreekChick]

Hey @ryanhamley! I updated my yarn version to 1.17.3 as well. I'm using node v11.6.0, though. I still see some changes to yarn.lock, but now the entire diff is 122 lines:

Elenis-MacBook-Pro : ~/mapbox-gl-js  (other/move-esm-to-dev-dependency)
🤓  git diff | wc -l
     122

I'll push my changes so they're visible here.

[DatGreekChick]

Ok... that didn't actually work like I expected given my bash output 🤣
It's either because I'm using a higher version of node (I suspect this isn't it) or simply because when I run yarn install it's updating the minor versions if there are any new ones with packages using ^.

[asheemmamoowala]

@DatGreekChick Could you rewrite your commit without the yarn.lock file?

[DatGreekChick]

@asheemmamoowala will do 👍

[DatGreekChick]

@asheemmamoowala I removed the yarn.lock file from the commit

[asheemmamoowala]

@mapbox/gl-native Do you still depend on esm from the gl-js package for running integration tests? If not, we'd like to get this PR merged

[mourner]

@asheemmamoowala looks like Native has esm in their devDeps, so we're safe to move to devDeps as well.

[DatGreekChick]

@ryanhamley can you dismiss your review?

yarn.lock removed from PR