Update package.json

Author: vlewin

package.json

@@ -1,6 +1,6 @@
 {
   "name": "serverless-step-functions",
-  "version": "1.6.0",
+  "version": "1.5.0",
   "description": "The module is AWS Step Functions plugin for Serverless Framework",
   "main": "lib/index.js",
   "scripts": {
@@ -32,7 +32,7 @@
     "istanbul": "^0.4.4",
     "mocha": "^5.2.0",
     "mocha-lcov-reporter": "^1.2.0",
-    "serverless": "^1.28.0",
+    "serverless": "^1.27.3",
     "sinon": "^1.17.5"
   },
   "dependencies": {