Options setting not work
Hi, thanks for the project first.

I want to set Coin-hive options (EX: threads、throttle)

And I tried with coinhive documentation example ,but it looks not working to set options in  Coin-hive

```
var miner = await CoinHive('my siteKey', {
        threads: 2,
        throttle: 0.8
    });
```
Can you give me some opinion? Thanks!

