Don't transpile to ES5

[vincentfretin]

We used @babel/preset-env without browserlist config in package.json, so @babel/preset-env defaulted to ES5 and not browserlist defaults query that applies modern browsers. See doc https://babeljs.io/docs/babel-preset-env https://babeljs.io/docs/options#no-targets but really nowadays we don't need to transpile to ES5, that was at a time we needed to support IE11. We don't use any fancy javascript syntax here, only ES6/ES2015 that is supported by all supported browsers.

Bundle size reduced from 521K to 426K. Transpiling to ES5 included lots of polyfills we don't need.

[vincentfretin]

I just had the idea to do this PR while watching https://www.youtube.com/watch?v=odhjF1obcUo

[vincentfretin]

To use it:

<a-scene inspector="url: https://cdn.jsdelivr.net/gh/aframevr/aframe-inspector@ddda46f4376cf696e623721d98e1c2eb3e799b73/dist/aframe-inspector.min.js">

[vincentfretin]

We could also just remove the single test https://github.com/aframevr/aframe-inspector/blob/master/src/components/tests/Collapsible.test.js and jest, babel-jest, react-test-renderer dependencies instead of reintroducing @babel/preset-env in https://github.com/aframevr/aframe-inspector/pull/772/commits/f8f9035ae935c7d8416b0126fa6f326d50c8242f @dmarcos thoughts?

[dmarcos]

Yeah we don't need to transpile to ES5 I think. Is this ready to merge?

[vincentfretin]

You can merge as is yes.

[dmarcos]

Thanks so much!