增加node版本

package.json

@@ -1,6 +1,12 @@
 {
   "name": "gateway",
   "version": "1.0.0",
+  "author": {
+    "email": "zsqmengzhihen@163.com",
+    "name": "zhusiqng"
+  },
+  "private": true,
+  "node": "^12.14.1",
   "keywords": [
     "node",
     "koa",