Bump parallel_tests from 3.0.0 to 3.1.0

Bumps [parallel_tests](https://github.com/grosser/parallel_tests) from 3.0.0 to 3.1.0.
- [Release notes](https://github.com/grosser/parallel_tests/releases)
- [Changelog](https://github.com/grosser/parallel_tests/blob/master/CHANGELOG.md)
- [Commits](grosser/parallel_tests@v3.0.0...v3.1.0)

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

Gemfile.lock

@@ -240,7 +240,7 @@ GEM
       rack
     orm_adapter (0.5.0)
     parallel (1.19.2)
-    parallel_tests (3.0.0)
+    parallel_tests (3.1.0)
       parallel
     parser (2.7.1.4)
       ast (~> 2.4.1)