title: How to get list of all countries and cities in rails?
body: <p>Is there a country and city gem where user will be able to select a country and based on selected country he will select a city?</p>
  
  <p>I get multiple solution but they all support states not cities</p>
  
  <pre><code>gem 'country_select'
  gem 'countries'
  gem 'carmen-rails'
  </code></pre>
  
  <p>I want a list of all countries on dropdown and when I select any country then all cities of country will appear in cities dropdown. Is this possible through any gem?</p>