fix(package): update pg to version 8.0.2

Closes #41

Author: greenkeeper[bot]

package.json

@@ -37,7 +37,7 @@
     "passport": "~0.4.0",
     "passport-local": "~1.0.0",
     "pdfkit": "~0.9.0",
-    "pg": "^7.4.3",
+    "pg": "^8.0.2",
     "pug": "^2.0.3",
     "q": "^1.4.1",
     "qr-image": "~3.2.0",