Merge branc 'dependabot/bundler/rexml-3.3.6' of 'https://github.com/chaoss/grimoirelab-tutorial'

Merges #233
Closes #233

Author: sduenas

Gemfile.lock

@@ -240,7 +240,8 @@ GEM
     rb-fsevent (0.11.0)
     rb-inotify (0.10.1)
       ffi (~> 1.0)
-    rexml (3.2.5)
+    rexml (3.3.6)
+      strscan
     rouge (3.26.0)
     ruby-enum (0.9.0)
       i18n
@@ -257,6 +258,7 @@ GEM
       faraday (> 0.8, < 2.0)
     simpleidn (0.2.1)
       unf (~> 0.1.4)
+    strscan (3.1.0)
     terminal-table (1.8.0)
       unicode-display_width (~> 1.1, >= 1.1.1)
     thread_safe (0.3.6)