Update rubocop, add appraisal gem

telegram-bot.gemspec

@@ -1,4 +1,3 @@
-# coding: utf-8
 lib = File.expand_path('../lib', __FILE__)
 $LOAD_PATH.unshift(lib) unless $LOAD_PATH.include?(lib)
 require 'telegram/bot/version'
@@ -20,9 +19,10 @@ Gem::Specification.new do |spec|
 
   spec.required_ruby_version = '~> 2.0'
 
-  spec.add_dependency 'activesupport', '>= 4.0', '< 5.2'
   spec.add_dependency 'actionpack', '>= 4.0', '< 5.2'
+  spec.add_dependency 'activesupport', '>= 4.0', '< 5.2'
   spec.add_dependency 'httpclient', '~> 2.7'
+
   spec.add_development_dependency 'bundler', '~> 1.11'
   spec.add_development_dependency 'rake', '~> 10.0'
 end