Merge branch 'dev' into dev-sxw

添加了后台比赛管理的api

template/oj/problem/problem.html

@@ -4,7 +4,7 @@
     <div class="container main">
         <ul class="nav nav-tabs nav-tabs-google">
             <li role="presentation" class="active">
-                <a href="problem.html">题目</a></li>
+                <a href="/problem/{{ problem.id }}/">题目</a></li>
             <li role="presentation"><a href="/problem/{{ problem.id }}/my_submissions/">我的提交</a></li>
         </ul>
         {% include "oj/problem/_problem_header.html" %}