add:教师端新增删除课程，增加并更换footer-brief模板

Html/apps/templates/course.html

@@ -46,7 +46,7 @@
             </div>
         </div>
     </div>
-         {% include 'foot.html' %}
+         {% include 'footer-brief.html' %}
 </body>
 <script>
     var course_id = "{{course_id}}";