Merge pull request #87 from coderdojo-japan/dependabot/bundler/rexml-3.4.2

Bump rexml from 3.4.1 to 3.4.2

Author: yasulab

Gemfile.lock

@@ -164,7 +164,7 @@ GEM
     rb-inotify (0.11.1)
       ffi (~> 1.0)
     redcarpet (3.6.1)
-    rexml (3.4.1)
+    rexml (3.4.2)
     rinku (2.0.6)
     rouge (4.5.2)
     ruby-rc4 (0.1.5)