Add the xmlns:xlink namespace to the root svg element

- This allows url linking to be used by the SVG child elements, which currently happens in <image> elements
diff --git a/player/js/renderers/SVGRendererBase.js b/player/js/renderers/SVGRendererBase.js
index 0768cf7..64fa08d 100644
--- a/player/js/renderers/SVGRendererBase.js
+++ b/player/js/renderers/SVGRendererBase.js
@@ -44,6 +44,7 @@
 
 SVGRendererBase.prototype.configAnimation = function (animData) {
   this.svgElement.setAttribute('xmlns', 'http://www.w3.org/2000/svg');
+  this.svgElement.setAttribute('xmlns:xlink', 'http://www.w3.org/1999/xlink');
   if (this.renderConfig.viewBoxSize) {
     this.svgElement.setAttribute('viewBox', this.renderConfig.viewBoxSize);
   } else {