Bump rexml from 3.2.5 to 3.3.0 (#326)

Author: chrisroos

Gemfile.lock

@@ -319,7 +319,8 @@ GEM
     rainbow (3.1.1)
     rake (13.0.6)
     regexp_parser (2.7.0)
-    rexml (3.2.5)
+    rexml (3.3.0)
+      strscan
     roo (2.10.1)
       nokogiri (~> 1)
       rubyzip (>= 1.3.0, < 3.0.0)
@@ -424,6 +425,7 @@ GEM
       activesupport (>= 5.2)
       sprockets (>= 3.0.0)
     stringio (3.0.5)
+    strscan (3.1.0)
     thor (1.2.1)
     tilt (2.3.0)
     time (0.3.0)