Explicit draw() call does not update internal state of the chart

**What you were expecting:**

After calling draw() with a scale parameter different than the current state of the chart, when a user tries to zoom/pan the chart it should zoom/scroll from the scale specified in the draw() call.

**What happened instead:**

After calling draw() with a scale parameter different than the current state of the chart, when a user tries to zoom/pan the chart it resets zoom and pan to the state it was before draw() was issued.

**Related code:**

https://jsfiddle.net/6rqxusw5/271/

```javascript
var scale = d3.scaleTime().domain([new Date('01/01/2017 12:00:00 AM'), new Date('02/01/2017 12:00:00 AM')]).range(chart.scale().range());
chart.draw(config, scale)(d3.select('#events').data([repositoriesData]));
```

**Environment**

* EventDrops version: 1.3.0
* Browser: Chrome, Firefox, Edge

Start with the JSFiddle reproduction and trace the chart.draw(config, scale) call alongside the chart's zoom and pan behavior. Confirm how the explicit scale is handled, then verify that a subsequent zoom or pan begins from the scale supplied to draw() rather than the previous internal state.

Written by the indexing model from the issue text.