Bump parser from 2.7.1.5 to 2.7.2.0

Bumps [parser](https://github.com/whitequark/parser) from 2.7.1.5 to 2.7.2.0.
- [Release notes](https://github.com/whitequark/parser/releases)
- [Changelog](https://github.com/whitequark/parser/blob/master/CHANGELOG.md)
- [Commits](whitequark/parser@v2.7.1.5...v2.7.2.0)

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

Gemfile.lock

@@ -51,7 +51,7 @@ GEM
       ice_nine (~> 0.11.1)
       procto (~> 0.0.2)
     os (1.1.1)
-    parser (2.7.1.5)
+    parser (2.7.2.0)
       ast (~> 2.4.1)
     procto (0.0.3)
     rake (13.0.1)