Bump rexml from 3.2.7 to 3.3.6 (#34)

Bumps [rexml](https://github.com/ruby/rexml) from 3.2.7 to 3.3.6.
- [Release notes](https://github.com/ruby/rexml/releases)
- [Changelog](https://github.com/ruby/rexml/blob/master/NEWS.md)
- [Commits](ruby/rexml@v3.2.7...v3.3.6)

---
updated-dependencies:
- dependency-name: rexml
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

Gemfile.lock

@@ -243,8 +243,8 @@ GEM
     rb-fsevent (0.11.0)
     rb-inotify (0.10.1)
       ffi (~> 1.0)
-    rexml (3.2.7)
-      strscan (>= 3.0.9)
+    rexml (3.3.6)
+      strscan
     rouge (3.26.0)
     ruby-enum (0.9.0)
       i18n