Merge pull request #591 from srobo/dependabot/bundler/rexml-3.3.9

Author: dependabot[bot]

Gemfile.lock

@@ -79,7 +79,7 @@ GEM
     rb-fsevent (0.11.2)
     rb-inotify (0.11.1)
       ffi (~> 1.0)
-    rexml (3.3.7)
+    rexml (3.3.9)
     rouge (3.30.0)
     safe_yaml (1.0.5)
     sass (3.7.4)