Bump rexml from 3.2.6 to 3.3.3 (#134)

Bumps [rexml](https://github.com/ruby/rexml) from 3.2.6 to 3.3.3.
- [Release notes](https://github.com/ruby/rexml/releases)
- [Changelog](https://github.com/ruby/rexml/blob/master/NEWS.md)
- [Commits](ruby/rexml@v3.2.6...v3.3.3)

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

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

Author: dependabot[bot]

Gemfile.lock

@@ -169,7 +169,8 @@ GEM
       io-console (~> 0.5)
     request_store (1.5.1)
       rack (>= 1.4)
-    rexml (3.2.6)
+    rexml (3.3.3)
+      strscan
     rspec-core (3.12.2)
       rspec-support (~> 3.12.0)
     rspec-expectations (3.12.3)
@@ -225,6 +226,7 @@ GEM
       activesupport (>= 5.2)
       sprockets (>= 3.0.0)
     stringio (3.1.0)
+    strscan (3.1.0)
     thor (1.3.0)
     timecop (0.9.8)
     tzinfo (2.0.6)