Add triggers

In case somebody will need triggers, here is what I do. 

Example: 

HTML
```
<h1 id="myTargetElement">0</h1>
<span id="status">0</span>
```

Javascript
```
function onTrigger(triggerValue) {
    document.getElementById("status").innerHTML = triggerValue;
}

var numAnim = new countUp("myTargetElement", 0, 99.99, 2, 3.5);
numAnim.addTriggers([70, 90], onTrigger); //or numAnim.addTriggers(70, onTrigger);
numAnim.start();
```

JSFiddle http://jsfiddle.net/u87Xg/3/