Add an index to CCCChanges table for the BalnceHistory API

Author: Park Juhyung

src/migrations/20191121090356-add-pagination-index-to-ccc-changes.js

@@ -0,0 +1,22 @@
+"use strict";
+
+const tableName = "CCCChanges";
+module.exports = {
+    up: async (queryInterface, Sequelize) => {
+        await queryInterface.addIndex(tableName, [
+            "address",
+            "reason",
+            "blockNumber",
+            "id"
+        ]);
+    },
+
+    down: async (queryInterface, Sequelize) => {
+        await queryInterface.removeIndex(tableName, [
+            "address",
+            "reason",
+            "blockNumber",
+            "id"
+        ]);
+    }
+};