version bump

Added History.md

- bumped version in `package.json`.  We are now working on `0.2.0`, which has
  some (minor) breaking changes from `0.1.0`.

Build Conductor

Tutorial setup.

Tutorial: Respond to data changes.

Tutorial: Update child card data.

Tutorial: Child cards.

```js
Playground.conductor.cards['../cards/tutorial/ad_card.js'][1][0].sandbox.videoPort.send('play');

// we add videoPort to window for convenience in the tutorial
window.videoPort.send('play');
```

Tutorial: YouTube card events.

One can send events from the playground via:
```js
Playground.conductor.cards['../cards/tutorial/youtube_card.js'][1][0].sandbox.videoPort.send('play');

// we add the video port to the window for convenience in the tutorial
window.videoPort.send('play');
```

Tutorial: Load YouTube API; showcase promises.

Tutorial: Create a youtube card.