fix(package): update pg to version 8.2.0

Closes #54

Author: greenkeeper[bot]

Diff for: package.json

@@ -17,7 +17,7 @@
     "debug": "^4.0.0",
     "express": "^4.16.2",
     "minio": "^7.0.3",
-    "pg": "^7.4.3",
+    "pg": "^8.2.0",
     "pg-hstore": "^2.3.2",
     "sequelize": "^4.22.6",
     "uuid": "^7.0.1"