add zk node type

escheduler-common/src/main/java/cn/escheduler/common/enums/ZKNodeType.java

@@ -0,0 +1,15 @@
+package cn.escheduler.common.enums;
+
+/**
+ * zk node type
+ */
+public enum ZKNodeType {
+
+    /**
+     * 0 do not send warning;
+     * 1 send if process success;
+     * 2 send if process failed;
+     * 3 send if process ending;
+     */
+    MASTER, WORKER, DEAD_SERVER, TASK_QUEUE;
+}