Charting small integers results in weird scale in v2.0

Creating a chart with only small integers results in a really weird scale.

This code in scale.linear.js is ending up with precision problems.

``` javascript
// Put the values into the ticks array
for (var j = niceMin; j <= niceMax; j += spacing) {
    this.ticks.push(j);
}
```

Here is an example [jsfiddle](https://jsfiddle.net/stevevanhorn/e9tzzhxw/)
