fukuzatsu.gemspec in fukuzatsu-2.1.1 vs fukuzatsu.gemspec in fukuzatsu-2.2.1

@@ -15,9 +15,10 @@
 
   spec.files         = `git ls-files -z`.split("\x0")
   spec.executables   = spec.files.grep(%r{^bin/}) { |f| File.basename(f) }
   spec.test_files    = spec.files.grep(%r{^(test|spec|features)/})
   spec.require_paths = ["lib"]
+  spec.required_ruby_version = '>= 2.1'
 
   spec.add_dependency "analyst", ">= 0.16.0"
   spec.add_dependency "ephemeral"
   spec.add_dependency "poro_plus"
   spec.add_dependency "haml"