title: How to set default locale in rails
body: <p>How do I set the default locale in rails application.rb so I don't have to add unit every time I call the following?</p>
  
  <pre><code>number_to_currency(@course.price, unit: "£") 
  </code></pre>
  
  <p>Rails guides says my locale is <code>:en-GB</code> for the UK, but the following obviously creates an error in application.rb</p>
  
  <pre><code>config.i18n.default_locale = :en-GB
  </code></pre>