add robot callback api

common/src/main/java/cn/wildfirechat/pojos/RobotCallbackPojo.java

@@ -0,0 +1,21 @@
+/*
+ * This file is part of the Wildfire Chat package.
+ * (c) Heavyrain2012 <[email protected]>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+package cn.wildfirechat.pojos;
+
+public class RobotCallbackPojo {
+    private String url;
+
+    public String getUrl() {
+        return url;
+    }
+
+    public void setUrl(String url) {
+        this.url = url;
+    }
+}