Start porting to 3.X line

[leodido]

Polymer 3 has been released and it is now on the npm registry.

Also polymer elements are now on the npm registry.

Everything is now using ES modules.

So we also should port the component to the 3.x line.

Any idea about the planning? @alelb and @leogr

[leogr]

We have to take in account that Material Design has been revamped (a.k.a. Material Design 2).
Also, PolymerElements are not yet ported to 3.0 nor to new Material Design.

I think we need a new repo for that.

[Protoss78]

Hi,

I just discovered your paper-chip component, forked it and tried to upgrade it using polymer modulizer. I got the component itself, the demo page and the iron-component-page working again after a few manual fixes of the automated migration. Only thing that is open is a migration of the tests.
I could provide a PR if you are still interested in fixing this issue?
You can have a look at the changes in my fork:
https://github.com/Protoss78/paper-chip-1

[leodido]

Hi @Protoss78 a PR would be really welcome!