aigu.gemspec in aigu-0.6.1 vs aigu.gemspec in aigu-0.7

@@ -16,9 +16,11 @@
   spec.files         = `git ls-files`.split($/)
   spec.executables   = 'aigu'
   spec.test_files    = spec.files.grep(%r{^(test|spec|features)/})
   spec.require_paths = ['lib']
 
+  spec.required_ruby_version = '~> 2.1'
+
   spec.add_development_dependency 'bundler', '~> 1.3'
   spec.add_development_dependency 'rake'
   spec.add_development_dependency 'rspec', '~> 3.0'
   spec.add_development_dependency 'phare', '~> 0.6'
   spec.add_development_dependency 'rubocop', '~> 0.27.0'