Bump rexml from 3.4.0 to 3.4.2

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]

Gemfile.lock

@@ -134,7 +134,7 @@ GEM
     regexp_parser (2.10.0)
     reline (0.6.0)
       io-console (~> 0.5)
-    rexml (3.4.0)
+    rexml (3.4.2)
     rspec-core (3.13.2)
       rspec-support (~> 3.13.0)
     rspec-expectations (3.13.3)