build(deps): update pg requirement from 7.6.1 to 7.7.1

Updates the requirements on [pg](https://github.com/brianc/node-postgres) to permit the latest version.
- [Release notes](https://github.com/brianc/node-postgres/releases)
- [Changelog](https://github.com/brianc/node-postgres/blob/master/CHANGELOG.md)
- [Commits](https://github.com/brianc/node-postgres/commits/v7.7.1)

Signed-off-by: dependabot[bot] <support@dependabot.com>

package.json

@@ -27,7 +27,7 @@
     "boom": "7.2.2",
     "csv-string": "3.1.5",
     "debug": "4.1.0",
-    "pg": "7.6.1",
+    "pg": "7.7.1",
     "pg-copy-streams": "1.2.0",
     "rimraf": "2.6.2",
     "upath": "1.1.0"