Remove Karma default install and add as an option

[newtriks]

Also add Jest as an option (or simply replace with Jest?).

[catalinmiron]

@newtriks jest is really, but really really slow. Right now, in our company we're trying to remove jest and move to karma :). So maybe, Jest as an option will be great ! 👍

[newtriks]

@catalinmiron thanks that's really good to know as I use Karma and have not yet tries Jest. Valuable input cheers!

[weblogixx]

Could be included in the new major version if wanted.