Gemfile in sass-zero-1.0.15 vs Gemfile in sass-zero-1.0.16

@@ -2,5 +2,7 @@
 
 git_source(:github) {|repo_name| "https://github.com/#{repo_name}" }
 
 # Specify your gem's dependencies in sass-zero.gemspec
 gemspec
+
+gem "rake", "~> 13.0"