Added style prop to the image

[multimeric]

Created to solve #1. Basically any props you add to the image-preloader component will be added to the child , allowing you to give the image a fixed height, for example:

var Image = require('react-image-preloader');
<Image 
             src="largeImage.jpg"
             fallback="smallImage.jpg"
             style={{
                 display: "inline-block",
                 height: 342,
                 width: 245
             }}
/>

[AVVS]

Please fix indent and add || '' so that when there is no style prop its not coerced to undefined