Gemfile in mail-notify-1.0 vs Gemfile in mail-notify-1.0.1

@@ -1,6 +1,6 @@
 # frozen_string_literal: true
 
-source 'https://rubygems.org'
+source "https://rubygems.org"
 
 # Specify your gem's dependencies in mail-notify.gemspec
 gemspec