Review Utils functions for refactor or whether they're still needed

[kingo55]

Some of the utils functions may be replaceable (arrayIndexOf, extend, keys):

https://github.com/kingo55/mojito-js-delivery/blob/9f313bd1ba59f1f8dcb80cc4df41b6b02b08f28c/lib/mojito.js#L515-L571

Older browsers are a dying breed and we probably don't need to offer shims for such old browsers that probably don't work on our clients' sites anyway.

[kingo55]

@allmywant do you think we need these three functions in the Utils lib? Or are there better ways of getting what we need here?

[allmywant]

@kingo55

• arrayIndexOf: native Array.indexOf is widely supported: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/indexOf#Browser_compatibility
• keys: Object.keys is widely supported too: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/keys#Browser_compatibility
• extend: we can replace it with Object.assign, but IE doesn't support this (https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/assign#Browser_compatibility). Since we just call extend once, we can remove it and do it in place where we call extend

Anyway I think all three functions can be removed.

[kingo55]

In the case of "extend", should we just leave that then?

It's probably easier to keep the utility function code separate from the constructor code.

I think the other two can probably be safely removed / replaced though.

[allmywant]

You're right @kingo55 , let's keep "extend" and remove arrayIndexOf, keys.

[kingo55]

Addressed by #80