chore: remove the use of regenerator in the build

[matuzalemsteles]

Well, we are deleting transform-regenerator so that we can use the Generator feature and consequently we can now also use async/await instead of continuing to use then for Promise, these are features that have been supported by the browser for a long time and is also included within our compatibility matrix.

• async/await - 95.9% https://caniuse.com/async-functions
• function* - 96.25% https://caniuse.com/es6-generators
• yield* - 95.15% https://caniuse.com/mdn-javascript_operators_yield_star
• yield - 95.15% https://caniuse.com/mdn-javascript_operators_yield

[matuzalemsteles]

cc @bryceosterhaus @ethib137

[bryceosterhaus]

This looks like it should fix out problems in DXP. I tested a local build too and verified that it no-longer requires a global of regeneratorRuntime

[bryceosterhaus]

Feel free to merge and publish a new version of clay and then I can test in DXP tomorrow.

[ethib137]

Would this fix the issue I've started seeing in codesandbox as well: https://codesandbox.io/s/language-selector-picker-example-iq811m?file=/src/index.js:0-66

[matuzalemsteles]

@ethib137 It's not possible to test on codesandbox yet because we haven't published the packages with this change yet, so we're just checking the build result locally.