Bump pg from 6.1.5 to 6.1.6
Bump pg from 6.1.5 to 6.1.6

Bumps [pg](https://github.com/brianc/node-postgres) from 6.1.5 to 6.1.6.
- [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/compare/v6.1.5...v6.1.6)

Signed-off-by: dependabot[bot] <5bdcd3c0d4d24ae3e71b3b452a024c6324c7e4bb@github.com>
apatitejs/apatite