Gulp 4 + Yarn

[hawkaa]

Hi there,

Thank you for an interesting project for working with point clouds in the browser.

I'm running on node v13.11.0 and npm 6.13.7 and had trouble getting your project running. It was related to the gulp version (https://stackoverflow.com/questions/55921442/how-to-fix-referenceerror-primordials-is-not-defined-in-node).

When upgrading gulp, I could not get npm to work either, so I added a yarn lockfile (these can live together, https://classic.yarnpkg.com/en/docs/migrating-from-npm/).

After upgrading gulp with yarn, I did the necessary changes in gulpfile.js.

Let me know what you think.