Remove jshint - move everything over to eslint

Also removed all hints of previous linters

js/views/scroll_down_button_view.js

@@ -1,26 +1,28 @@
+/* global Whisper, i18n */
+
+// eslint-disable-next-line func-names
 (function() {
   'use strict';
+
   window.Whisper = window.Whisper || {};
 
   Whisper.ScrollDownButtonView = Whisper.View.extend({
     className: 'scroll-down-button-view',
     templateName: 'scroll-down-button-view',
 
-    initialize: function(options) {
-      options = options || {};
+    initialize(options = {}) {
       this.count = options.count || 0;
     },
 
-    increment: function(count) {
-      count = count || 0;
+    increment(count = 0) {
       this.count += count;
       this.render();
     },
 
-    render_attributes: function() {
-      var cssClass = this.count > 0 ? 'new-messages' : '';
+    render_attributes() {
+      const cssClass = this.count > 0 ? 'new-messages' : '';
 
-      var moreBelow = i18n('scrollDown');
+      let moreBelow = i18n('scrollDown');
       if (this.count > 1) {
         moreBelow = i18n('messagesBelow');
       } else if (this.count === 1) {
@@ -28,8 +30,8 @@
       }
 
       return {
-        cssClass: cssClass,
-        moreBelow: moreBelow,
+        cssClass,
+        moreBelow,
       };
     },
   });