chore(deps): bump rexml from 3.2.5 to 3.2.6

Bumps [rexml](https://github.com/ruby/rexml) from 3.2.5 to 3.2.6.
- [Release notes](https://github.com/ruby/rexml/releases)
- [Changelog](https://github.com/ruby/rexml/blob/master/NEWS.md)
- [Commits](https://github.com/ruby/rexml/compare/v3.2.5...v3.2.6)

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

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

Gemfile.lock

@@ -570,7 +570,7 @@ GEM
     responders (3.1.0)
       actionpack (>= 5.2)
       railties (>= 5.2)
-    rexml (3.2.5)
+    rexml (3.2.6)
     roadie (5.0.1)
       css_parser (~> 1.4)
       nokogiri (~> 1.8)