Require MFA to release thor

Author: rafaelfranca

thor.gemspec

@@ -18,7 +18,8 @@ Gem::Specification.new do |spec|
     "changelog_uri" => "https://github.com/rails/thor/releases/tag/v#{Thor::VERSION}",
     "documentation_uri" => "http://whatisthor.com/",
     "source_code_uri" => "https://github.com/rails/thor/tree/v#{Thor::VERSION}",
-    "wiki_uri" => "https://github.com/rails/thor/wiki"
+    "wiki_uri" => "https://github.com/rails/thor/wiki",
+    "rubygems_mfa_required" => "true",
   }
   spec.require_paths = %w(lib)
   spec.required_ruby_version = ">= 2.0.0"