Bump graphql from 2.2.4 to 2.2.7

Bumps [graphql](https://github.com/rmosolgo/graphql-ruby) from 2.2.4 to 2.2.7.
- [Release notes](https://github.com/rmosolgo/graphql-ruby/releases)
- [Changelog](https://github.com/rmosolgo/graphql-ruby/blob/master/CHANGELOG.md)
- [Commits](rmosolgo/graphql-ruby@v2.2.4...v2.2.7)

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

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

Gemfile.lock

@@ -16,8 +16,7 @@ GEM
     diff-lcs (1.5.0)
     docile (1.4.0)
     e2mmap (0.1.0)
-    graphql (2.2.4)
-      racc (~> 1.4)
+    graphql (2.2.7)
     haml (6.3.0)
       temple (>= 0.8.2)
       thor