initial attempt to add right click action

I am trying to add a right click action to DalekJS. Current commit doesn't perform a right click action.

I am trying to send a `{button = 2}` parameter to a WebDriver API [according to the W3C documentation](https://dvcs.w3.org/hg/webdriver/raw-file/default/webdriver-spec.html#methods-15)

I tried the following options with no result:

```javascript
var rightButton = {'button': '2'};
var rightButton = 'right';
var rightButton = '2';
```
I am guessing that [this line](https://github.com/dalekjs/dalek/blob/master/lib/dalek/actions.js#L1324) doesn't call WebDriver API directly, does it? What shall I do in order to pass `{button = 2}` parameter further to the WebDriver API?


> P.S.
> traling spaces are removed as specified in the `.editorconfig` file.