rename cache keys.

examcloud-core-oe-admin-base/src/main/java/cn/com/qmth/examcloud/core/oe/admin/base/Constants.java

@@ -8,6 +8,8 @@ package cn.com.qmth.examcloud.core.oe.admin.base;
  */
 public interface Constants {
 
+    int TIME_OUT_7_DAY = 60 * 60 * 24 * 7;
+
     /**
      * 系统错误
      */