Bump parallel from 1.15.0 to 1.16.0 in /Library/Homebrew

Bumps [parallel](https://github.com/grosser/parallel) from 1.15.0 to 1.16.0.
- [Release notes](https://github.com/grosser/parallel/releases)
- [Commits](grosser/parallel@v1.15.0...v1.16.0)

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

Library/Homebrew/Gemfile.lock

@@ -48,7 +48,7 @@ GEM
     nokogiri (1.10.2)
       mini_portile2 (~> 2.4.0)
     ntlm-http (0.1.1)
-    parallel (1.15.0)
+    parallel (1.16.0)
     parallel_tests (2.28.0)
       parallel
     parser (2.6.2.0)