Alter line height regular expression

There will be 4 line heights in the Text Widget - Single, 1.15, 1.5 and Double (same as how Google docs does it). To implement this, the editor requires a CSS class for each one, and I'm struggling a little with the naming of the 1.15 and 1.5 classes. Right now I'm planning to use:
```
.wysiwyg-line-height-one-point-one-five {
  line-height: 1.15;
}
.wysiwyg-line-height-one-point-five {
  line-height: 1.5;
}
```

I'm not really a fan of this though as it ties the class name to the value used for the line height. Anyone have better ideas for naming the 1.15 and 1.5 classes?

@winkerVSbecks @alex-deaconu @stulees Please review. Thx.