Makes iframes responsive, I mainly use this for video embeds.
loops through all iframe elements within containerElement
$(containerElement).responsiveIframes({
excludeClasses: '.resize-exclude,.instagram-media,.fb_iframe_widget,.twitter-tweet,.flickr-embed-frame', // iframes with these classes will be excluded from resizing
closestParent: '.content', // the closest parent element to get the target width from.
verticalCenter: false, // should the video scale to the available height and center itself, instead of scaling to width,
verticalCenterMin: 500 // min width that vertical center will work with.
});