Gemfile in jekyll-postcss-0.1.0 vs Gemfile in jekyll-postcss-0.2.0

@@ -1,2 +1,4 @@
-source 'https://rubygems.org'
+# frozen_string_literal: true
+
+source "https://rubygems.org"
 
 # Specify your gem's dependencies in jekyll-postcss.gemspec