chore(package): update pg-promise to version 5.3.1 (#2519)

https://greenkeeper.io/

Author: greenkeeperio-bot

package.json

@@ -36,7 +36,7 @@
     "parse-server-push-adapter": "1.0.4",
     "parse-server-s3-adapter": "1.0.4",
     "parse-server-simple-mailgun-adapter": "1.0.0",
-    "pg-promise": "5.2.7",
+    "pg-promise": "5.3.1",
     "redis": "2.6.2",
     "request": "2.74.0",
     "semver": "5.2.0",