Gemfile in mojo_magick-0.6.2 vs Gemfile in mojo_magick-0.6.3

@@ -1,8 +1,8 @@
 source "https://rubygems.org"
 
 group :test, :development do
-  gem 'irb', require: false
-  gem 'simplecov', require: false
+  gem "irb", require: false
+  gem "simplecov", require: false
 end
 
 gemspec