Merge pull request #11 from coderdojo-japan/dependabot/bundler/rexml-3.3.3

Bump rexml from 3.3.2 to 3.3.3

Author: jun1waka

Gemfile.lock

@@ -120,7 +120,7 @@ GEM
     rb-inotify (0.10.1)
       ffi (~> 1.0)
     redcarpet (3.6.0)
-    rexml (3.3.2)
+    rexml (3.3.3)
       strscan
     rinku (2.0.6)
     rouge (4.1.2)