Merge branch 'dependabot/bundler/nokogiri-1.13.9' of 'https://github.com/chaoss/grimoirelab-tutorial'

Merges #217
Closes #217

Author: sduenas

Gemfile.lock

@@ -228,7 +228,7 @@ GEM
       jekyll-seo-tag (~> 2.1)
     minitest (5.14.4)
     multipart-post (2.1.1)
-    nokogiri (1.13.6)
+    nokogiri (1.13.9)
       mini_portile2 (~> 2.8.0)
       racc (~> 1.4)
     octokit (4.21.0)