Bump pg from 1.6.2 to 1.6.3

Bumps [pg](https://github.com/ged/ruby-pg) from 1.6.2 to 1.6.3.
- [Changelog](https://github.com/ged/ruby-pg/blob/master/CHANGELOG.md)
- [Commits](ged/ruby-pg@v1.6.2...v1.6.3)

---
updated-dependencies:
- dependency-name: pg
  dependency-version: 1.6.3
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

Author: dependabot[bot]

Gemfile.lock

@@ -486,8 +486,8 @@ GEM
       racc
     percy-capybara (5.0.0)
       capybara (>= 3)
-    pg (1.6.2)
-    pg (1.6.2-x86_64-linux)
+    pg (1.6.3)
+    pg (1.6.3-x86_64-linux)
     platform-api (3.8.0)
       heroics (~> 0.1.1)
       moneta (~> 1.0.0)