Adding outline styles (none) to the sr focus div

lms/static/sass/course/courseware/_courseware.scss

@@ -60,6 +60,12 @@ div.course-wrapper {
       }
     }
 
+    #sr-is-focusable,
+    #sr-is-focusable:focus,
+    #sr-is-focusable:active {
+      outline: none;
+    }
+
     .sequential-status-message {
       margin-bottom: $baseline;
       background-color: $gray-l5;