Add accessible menu names

analytics_dashboard/templates/header.html

@@ -36,6 +36,7 @@ Partial: App-wide header element
         <li class="dropdown">
           <button class="dropdown-toggle active-user navbar-link" data-toggle="dropdown"
              aria-controls="userDropdownMenu" id="userMenu">
+            <span class="sr-only">{% trans "Menu for" %}</span>
             <span class="ico-user fa fa-graduation-cap" aria-hidden="true"></span>
             <span class="active-user-name">{{ request.user.username }}</span>
             <span class="ico ico-indicator fa fa-caret-down" aria-hidden="true"></span>

analytics_dashboard/templates/lens-navigation.html

@@ -12,6 +12,7 @@ Partial for displaying the lens navigation and the sections within the lenses.
           <button class="dropdown-toggle navbar-link" data-toggle="dropdown" id="lensPrimaryMenu"
               aria-controls="lensDropdownMenu">
             <span class="link-label">
+            <span class="sr-only">{% trans "Lens Menu." %}</span>
             <span class="ico fa {{ primary_nav_item.icon }}" aria-hidden="true"></span>
             {{ primary_nav_item.label }}
             {# Translators: This refers to the active tab/navigation item. #}