Release should use invoke not execute

release task only have prerequisites so we need to call invoke to
execute them.

Author: rafaelfranca

Thorfile

@@ -19,7 +19,7 @@ class Default < Thor
 
   desc "release", "Create tag v#{Thor::VERSION} and build and push thor-#{Thor::VERSION}.gem to Rubygems"
   def release
-    Rake::Task["release"].execute
+    Rake::Task["release"].invoke
   end
 
   desc "spec", "Run RSpec code examples"