Minifying es6

[rangeoshun]

I'd like to add the package diffDOM to cljsjs/packages. It does not provide minified version, so would like to minify it with the built-in task. It fails due to the fact that the minify only provides an option that specifies language-in. Setting this to ES6 results in the following error message:

ES6 is only supported for transpilation to a lower ECMAScript version. Set --language_out to ES3, ES5, or ES5_STRICT.

Since yesterday, it is possible to specify both language-in and language-out for asset-minifier through this PR. With the default in being :ecmascript6 and :ecmascript5 as output.

[rangeoshun]

Thanks for the merge @Deraen ! What's next? Should I just use v0.10.3 in my package, or you'd like to update them all?

[Deraen]

I updated all deps now, but in such cases it is also fine to start using new version in single package as needed.

[rangeoshun]

Ok, will remember that. Did you not update lang option on purpose? I mean it should be still ok, just the output language won't be as expected in some cases. That is if lang is set to es3, it'll be es5 instead. Thanks, I just saw, it's not an issue as no package does this.