[Proposal] Remove ES2015 preset when Node 6 active LTS

[jhen0409]

Node 6 will active LTS in Oct 2016 (see this), and currently Electron is used Node 6 as runtime, we can only keep transform-es2015-modules-commonjs plugin. (It's not required in the Webpack 2)

Also, the problems:

• Currently uglify is not supported ES2015 syntax (we can watching the discussion)
• Currently object-rest-spread is need destructuring transform, see Doesn't work with transform-object-rest-spread jhen0409/babel-preset-es2015-node6#2 and Babel#T7086. In fact, I once said to fix it, but no chance yet. :\

[amilajack]

We should use https://github.com/babel/babel-preset-env

[jhen0409]

Yeah I think we should pointing to babel-preset-env and babili, and require node ^6 here, waiting for babel/babel#4755 merged, I'll do this.

[amilajack]

Apparently its in beta. For the most part, I think it should be stable enough. What about you?

[hzoo]

You can always check the actual transforms with debug and then check that against the compat-table

[amilajack]

@hzoo which compat table? Also do you think babli is stable enough to be used in production?

[hzoo]

https://github.com/kangax/compat-table is where the env data comes from - babili is still in beta but the more people testing it out the better so we can fix the bugs to make it more stable