v1.1.0 - Push notification support - beta v1

See https://www.ably.io/documentation/realtime/push for details on how to use Ably's native push notifications.

This PR adds push notification support to the Ably JS library.

Note that Push notifications support is currently in public beta. The API may change before the final release. Please report any bugs or feedback to support@ably.io

Installation instructions

• Clone the repository (git clone https://github.com/ably/ably-js.git)
• Check out the push branch (git fetch origin push && git checkout push)
• For node: require nodejs/index.js from your code (e.g. const Ably = require('relative/path/to/ably-js/nodejs/index.js');)
• For browsers:
  • For webpack: require browser/static/ably.js from your code (e.g. const Ably = require('relative/path/to/ably-js/browser/static/ably.js');)
  • For use with a script tag: upload browser/static/ably.js somewhere accessible and source it as normal