chore(ci): GitHub Pages runs Ruby 2.7.1

Author: DirtyF

.travis.yml

@@ -8,7 +8,7 @@ env:
 matrix:
   include:
     - # GitHub Pages
-      rvm: 2.5.3
+      rvm: 2.7.1
       env: GH_PAGES=true
     - rvm: *latest_ruby
       env: JEKYLL_VERSION="~> 4.0"