change right menu icon on mobile from hamburger to chevron

app/assets/javascripts/application.js.coffee

@@ -205,6 +205,15 @@ $ ->
     $('.header-content .navbar-collapse').toggle()
     $('.navbar-toggle').toggleClass('active')
+    navIcon = $('.navbar-toggle').find('.fa')
+
+    if $(navIcon).hasClass('fa-chevron-left')
+      $(navIcon).removeClass('fa-chevron-left')
+      $(navIcon).addClass('fa-chevron-right')
+    else
+      $(navIcon).removeClass('fa-chevron-right')
+      $(navIcon).addClass('fa-chevron-left')
+
   # Show/hide comments on diff
   $("body").on "click", ".js-toggle-diff-comments", (e) ->
     $(@).toggleClass('active')

app/views/layouts/header/_default.html.haml

@@ -3,7 +3,7 @@
     .header-content
       %button.navbar-toggle{type: 'button'}
         %span.sr-only Toggle navigation
-        = icon('bars')
+        = icon('chevron-left')
       .navbar-collapse.collapse
         %ul.nav.navbar-nav