chore(scripts/publish): get dist-tag from package.json

[petebacondarwin]

This change would need to be cherry-picked to the previous version branches (with suitable change to package.json) to prevent releases from them breaking npm dist-tags.

Where does this need to be documented? New big version release tasks? Contributor documentation?

[petebacondarwin]

The branch to dist-tag mapping will be as follows (once we fork and start working on 1.5.0):

• 1.2.x -> ie8_compat
• 1.3.x -> previous_1_3
• 1.4.x -> latest
• master -> beta

[Narretz]

I think it's okay, although it's a bit cumbersome to update the branches.
Do we have access to our git in this step? Then we could check if there's a larger version number, and not set it in this case.

[petebacondarwin]

Going forward it will be quite straightforward. You only ever have to change the branch that is going from latest to previous... and then master swaps between latest and beta. We need to specify some dist-tag when publishing or it defaults to latest

[IgorMinar]

nice! lgtm