Bump tokio-postgres from 0.7.11 to 0.7.12

Bumps [tokio-postgres](https://github.com/sfackler/rust-postgres) from 0.7.11 to 0.7.12.
- [Release notes](https://github.com/sfackler/rust-postgres/releases)
- [Commits](sfackler/rust-postgres@tokio-postgres-v0.7.11...tokio-postgres-v0.7.12)

---
updated-dependencies:
- dependency-name: tokio-postgres
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <[email protected]>