bump Rake to 13.0.6

Author: robjlucas

envied.gemspec

@@ -33,6 +33,6 @@ Gem::Specification.new do |spec|
 
   spec.add_development_dependency "bundler", "~> 2.0"
   spec.add_development_dependency "pry", "~> 0.12"
-  spec.add_development_dependency "rake", "~> 12.0"
+  spec.add_development_dependency "rake", "~> 13.0.6"
   spec.add_development_dependency "rspec", "~> 3.0"
 end