Removed unneeded dependencies.

Also updated Gulp build

Author: cferdinandi

dist/_closest.polyfill.js

@@ -0,0 +1,24 @@
+/*!
+ * smooth-scroll v15.1.1
+ * Animate scrolling to anchor links
+ * (c) 2018 Chris Ferdinandi
+ * MIT License
+ * http://github.com/cferdinandi/smooth-scroll
+ */
+
+/**
+ * closest() polyfill
+ * @link https://developer.mozilla.org/en-US/docs/Web/API/Element/closest#Polyfill
+ */
+if (window.Element && !Element.prototype.closest) {
+	Element.prototype.closest = function(s) {
+		var matches = (this.document || this.ownerDocument).querySelectorAll(s),
+			i,
+			el = this;
+		do {
+			i = matches.length;
+			while (--i >= 0 && matches.item(i) !== el) {}
+		} while ((i < 0) && (el = el.parentElement));
+		return el;
+	};
+}

dist/_closest.polyfill.min.js

@@ -0,0 +1,27 @@
+/*!
+ * smooth-scroll v15.1.1
+ * Animate scrolling to anchor links
+ * (c) 2018 Chris Ferdinandi
+ * MIT License
+ * http://github.com/cferdinandi/smooth-scroll
+ */
+
+/**
+ * CustomEvent() polyfill
+ * https://developer.mozilla.org/en-US/docs/Web/API/CustomEvent/CustomEvent#Polyfill
+ */
+(function () {
+
+	if (typeof window.CustomEvent === "function") return false;
+
+	function CustomEvent(event, params) {
+		params = params || { bubbles: false, cancelable: false, detail: undefined };
+		var evt = document.createEvent('CustomEvent');
+		evt.initCustomEvent(event, params.bubbles, params.cancelable, params.detail);
+		return evt;
+	}
+
+	CustomEvent.prototype = window.Event.prototype;
+
+	window.CustomEvent = CustomEvent;
+})();

dist/_customEvent.polyfill.js

@@ -0,0 +1,41 @@
+/*!
+ * smooth-scroll v15.1.1
+ * Animate scrolling to anchor links
+ * (c) 2018 Chris Ferdinandi
+ * MIT License
+ * http://github.com/cferdinandi/smooth-scroll
+ */
+
+/**
+ * requestAnimationFrame() polyfill
+ * By Erik Möller. Fixes from Paul Irish and Tino Zijdel.
+ * @link http://paulirish.com/2011/requestanimationframe-for-smart-animating/
+ * @link http://my.opera.com/emoller/blog/2011/12/20/requestanimationframe-for-smart-er-animating
+ * @license MIT
+ */
+(function() {
+	var lastTime = 0;
+	var vendors = ['ms', 'moz', 'webkit', 'o'];
+	for(var x = 0; x < vendors.length && !window.requestAnimationFrame; ++x) {
+		window.requestAnimationFrame = window[vendors[x]+'RequestAnimationFrame'];
+		window.cancelAnimationFrame = window[vendors[x]+'CancelAnimationFrame'] ||
+		                              window[vendors[x]+'CancelRequestAnimationFrame'];
+	}
+
+	if (!window.requestAnimationFrame) {
+		window.requestAnimationFrame = function(callback, element) {
+			var currTime = new Date().getTime();
+			var timeToCall = Math.max(0, 16 - (currTime - lastTime));
+			var id = window.setTimeout((function() { callback(currTime + timeToCall); }),
+				timeToCall);
+			lastTime = currTime + timeToCall;
+			return id;
+		};
+	}
+
+	if (!window.cancelAnimationFrame) {
+		window.cancelAnimationFrame = function(id) {
+			clearTimeout(id);
+		};
+	}
+}());

dist/_customEvent.polyfill.min.js

@@ -1,5 +1,6 @@
 /*!
- * smooth-scroll v15.1.0: Animate scrolling to anchor links
+ * smooth-scroll v15.1.1
+ * Animate scrolling to anchor links
  * (c) 2018 Chris Ferdinandi
  * MIT License
  * http://github.com/cferdinandi/smooth-scroll
@@ -105,21 +106,6 @@
 		return parseInt(window.getComputedStyle(elem).height, 10);
 	};
 
-	/**
-	 * Decode a URI, with error check
-	 * @param  {String} hash The URI to decode
-	 * @return {String}      A decoded URI (or the original string if an error is thrown)
-	 */
-	var decode = function (hash) {
-		var decoded;
-		try {
-			decoded = decodeURIComponent(hash);
-		} catch(e) {
-			decoded = hash;
-		}
-		return decoded;
-	};
-
 	/**
 	 * Escape special characters for use with querySelector
 	 * @author Mathias Bynens
@@ -196,13 +182,7 @@
 		}
 
 		// Return sanitized hash
-		var hash;
-		try {
-			hash = decodeURIComponent('#' + result);
-		} catch(e) {
-			hash = '#' + result;
-		}
-		return hash;
+		return '#' + result;
 
 	};
 
@@ -535,7 +515,7 @@
 			if (toggle.hostname !== window.location.hostname || toggle.pathname !== window.location.pathname || !/#/.test(toggle.href)) return;
 
 			// Get an escaped version of the hash
-			var hash = escapeCharacters(decode(toggle.hash));
+			var hash = escapeCharacters(toggle.hash);
 
 			// Get the anchored element
 			var anchor = settings.topOnEmptyHash && hash === '#' ? document.documentElement : document.querySelector(hash);
@@ -568,7 +548,7 @@
 			// Get the anchor
 			var anchor = history.state.anchor;
 			if (anchor && anchor !== 0) {
-				anchor = document.querySelector(escapeCharacters(decode(history.state.anchor)));
+				anchor = document.querySelector(escapeCharacters(history.state.anchor));
 				if (!anchor) return;
 			}