Bump pg from 1.1.4 to 1.2.0 (#1509)

Bumps [pg](https://github.com/ged/ruby-pg) from 1.1.4 to 1.2.0.
- [Release notes](https://github.com/ged/ruby-pg/releases)
- [Changelog](https://github.com/ged/ruby-pg/blob/master/History.rdoc)
- [Commits](ged/ruby-pg@v1.1.4...v1.2.0)

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

Gemfile.lock

@@ -148,7 +148,7 @@ GEM
       mini_portile2 (~> 2.4.0)
     parser (2.6.2.1)
       ast (~> 2.4.0)
-    pg (1.1.4)
+    pg (1.2.0)
     poltergeist (1.18.1)
       capybara (>= 2.1, < 4)
       cliver (~> 0.3.1)