ES modules build in npm

[c01nd01r]

Vue.js version

2.2.0

Reproduction Link

https://github.com/vuejs/vue/blob/dev/package.json#L9-L21

What is Expected?

esm build files in npm package

What is actually happening?

vue.runtime.esm.js and vue.esm.js are missing in npm package

Hi!
Thanks for new release, but I can't find new ES modules build files in npm package.
Seems like, this files missing from package.json in files field?

[c01nd01r]

#5009

[yyx990803]

Published 2.0.1.