build(deps-dev): bump pg from 1.3.5 to 1.4.0

Bumps [pg](https://github.com/ged/ruby-pg) from 1.3.5 to 1.4.0.
- [Release notes](https://github.com/ged/ruby-pg/releases)
- [Changelog](https://github.com/ged/ruby-pg/blob/master/History.rdoc)
- [Commits](ged/ruby-pg@v1.3.5...v1.4.0)

---
updated-dependencies:
- dependency-name: pg
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

Gemfile.lock

@@ -350,7 +350,7 @@ GEM
       parallel
     parser (3.1.2.0)
       ast (~> 2.4.1)
-    pg (1.3.5)
+    pg (1.4.0)
     posix-spawn (0.3.15)
     protobuf (3.6.12)
       activesupport (>= 3.2)