title: rails model with multiple related addresses
body: <p>I have the following rails models:</p>
  
  <pre><code># Address Model
  address_line_1
  address_line_2
  address_line_3
  post_code
  country
  
  # Vendor model
  name
  registered_address_id
  billing_address_id
  display_address_id
  </code></pre>
  
  <p>registered_address, billing_address and display_address should refer to an address in the address table.</p>
  
  <p>so eventually I can do Vendor.registered_address etc.</p>
  
  <p>I am confused about how to go about this with regards to migrations and my relationships on my model, can anyone point me in the right direction?</p>
  
  <p>Many thanks</p>