Remove responsive file since it is not necessary

src/core/core.responsive.js

@@ -1,29 +0,0 @@
-(function() {
-
-	"use strict";
-
-	//Declare root variable - window in the browser, global on the server
-	var root = this,
-		previous = root.Chart,
-		helpers = Chart.helpers;
-
-
-	// Attach global event to resize each chart instance when the browser resizes
-	helpers.addEvent(window, "resize", (function() {
-		// Basic debounce of resize function so it doesn't hurt performance when resizing browser.
-		var timeout;
-		return function() {
-			clearTimeout(timeout);
-			timeout = setTimeout(function() {
-				helpers.each(Chart.instances, function(instance) {
-					// If the responsive flag is set in the chart instance config
-					// Cascade the resize event down to the chart.
-					if (instance.options.responsive) {
-						instance.resize();
-					}
-				});
-			}, 16);
-		};
-	})());
-
-}).call(this);