Describe the bug

The minified "lib\browser\math.js" in published NPM package includes the code for some dev dependencies !

To Reproduce

Do an NPM install in blank folder

Navigate to ".\node_modules\mathjs\lib\browser"

If you open "math.js" you can find code that creates ActiveXObject and plays with "iframe"
that actually comes from core-js "/internals/object-create.js" file
(I only saw it because it was wrongly reported to me as a Trojan).

And if you open "math.js.map" you will find it lists lots of files from core-js package.

But core-js is only a dev-dependency it should not be included in published version.

Best regards.