remove required ruby version from gemspec

Author: delabiejochen

testingbot.gemspec

@@ -25,7 +25,6 @@ Gem::Specification.new do |gem|
 
   gem.license = 'MIT'
 
-  gem.required_ruby_version = '~> 2.0'
   gem.add_runtime_dependency 'rest-client', '~> 2.0'
   gem.add_runtime_dependency 'json'
   gem.add_development_dependency "rspec", '~> 3.3'