Adding stroke lines for chips

[jeanpaulpacheco]

Would it be possible to implement the option to add chip borders in the form of stroke? Looking at Material Design, we are given two types of chips samples:

• Chip with solid background
• Chip with clear/white background and a grey stroke
  https://storage.googleapis.com/spec-host-backup/mio-design%2Fassets%2F1bqMzV-lgxi6GhC8zF6MrxLHtReMV1S_b%2Fchips-types-entry.png

Because of this, I'm proposing the addition of 2 new properties - chipStrokeWidth and chipStrokeColor

I have tried this locally and it does not it's not a big change to implement this, so I could push a branch and PR for this as well, but I wanted some input on the matter beforehand.

[jeanpaulpacheco]

I have the implementation in a fork - https://github.com/jeanpaulpacheco/nachos/commit/2ef6edd95ea2eb18407c944b91cbd30c7de2f47b