chore(deps): update dependency serverless to v1.50.0

Author: renovate-bot

package.json

@@ -103,7 +103,7 @@
     "prettier": "1.18.2",
     "prettier-eslint": "8.8.2",
     "rimraf": "2.7.0",
-    "serverless": "1.49.0",
+    "serverless": "1.50.0",
     "serverless-domain-manager": "2.6.13",
     "serverless-offline": "4.10.6",
     "serverless-plugin-aws-alerts": "1.4.0",