Update rake dependency to avoid security warning

Gemfile

@@ -13,6 +13,14 @@ branch = File.read(File.expand_path("../maintenance-branch", __FILE__)).chomp
   end
 end
 
+if RUBY_VERSION < '1.9.3'
+  gem 'rake', '< 11.0.0' # rake 11 requires Ruby 1.9.3 or later
+elsif RUBY_VERSION < '2.0.0'
+  gem 'rake', '< 12.0.0' # rake 12 requires Ruby 2.0.0 or later
+else
+  gem 'rake', '>= 12.3.2'
+end
+
 ### dep for ci/coverage
 gem 'simplecov', '~> 0.8'
 

rspec-support.gemspec

@@ -35,6 +35,6 @@ Gem::Specification.new do |spec|
 
   spec.required_ruby_version = '>= 1.8.7'
 
-  spec.add_development_dependency "rake",         "~> 10.0.0"
+  spec.add_development_dependency "rake",         "> 10.0.0"
   spec.add_development_dependency "thread_order", "~> 1.1.0"
 end