Bump rexml from 3.4.0 to 3.4.2 in /.github/DangerFiles

Bumps [rexml](https://github.com/ruby/rexml) from 3.4.0 to 3.4.2.
- [Release notes](https://github.com/ruby/rexml/releases)
- [Changelog](https://github.com/ruby/rexml/blob/master/NEWS.md)
- [Commits](ruby/rexml@v3.4.0...v3.4.2)

---
updated-dependencies:
- dependency-name: rexml
  dependency-version: 3.4.2
  dependency-type: indirect
...

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

Author: dependabot[bot]

.github/DangerFiles/Gemfile.lock

@@ -63,7 +63,7 @@ GEM
     pstore (0.1.4)
     public_suffix (6.0.1)
     rchardet (1.9.0)
-    rexml (3.4.0)
+    rexml (3.4.2)
     ruby-ll (2.1.3)
       ansi
       ast