Added lerna-alias dep to automate creating jest aliases

[Andarist]

What:
Added lerna-alias dependency and used it in jest configs

Why:
To automate generating those aliases

Checklist:

• Documentation N/A
• Tests
• Code complete

@mitchellhamilton regarding #464 (comment) - could u point me to the rollup.config.js in which you have wanted to use it? would love to see what's happening to fix the issue

[emmatown]

Thanks!! The rollup config is in the repo root(only the UMD bit, where alias is already used), I'm guessing the problem was that the cwd was in the individual packages so passing __dirname to lerna-alias would probably fix it.