Fix eslint errors

index.js

@@ -1,12 +1,14 @@
-(function ($) {
+/* global jQuery */
+
+(($) => {
 
     $.fn.aalert = function (method) {
         if (methods[method]) {
             return methods[method].apply(this, Array.prototype.slice.call(arguments, 1));
-        } else {
-            $.error('Method ' + method + ' does not exist');
-            return false;
         }
+
+        $.error('Method ' + method + ' does not exist');
+        return false;
     };
 
     var methods = {
@@ -58,7 +60,7 @@
                 $this.hide();
             }
 
-            if ( $this.hasClass('remove')) {
+            if ($this.hasClass('remove')) {
                 $this.remove();
             }
 
@@ -69,7 +71,7 @@
             var $this = $(this);
             if ($this.hasClass('fade')) {
                 $this.fadeIn();
-            } else if ( $this.hasClass('slide')) {
+            } else if ($this.hasClass('slide')) {
                 $this.slideDown();
             } else {
                 $this.show();
@@ -90,7 +92,7 @@
     };
 
     $('.alert [data-dismiss="aalert"]').click(e => {
-        $element = $(e.target).closest('.alert');
+        var $element = $(e.target).closest('.alert');
         methods.close.apply($element);
     });