title: Check if a table exists in Rails
body: <p>I have a rake task that won't work unless a table exists. I'm working with more than 20 engineers on a website so I want to make sure they have migrated the table before they can do a rake task which will populate that respective table.</p>
  
  <p>Does AR have a method such as <code>Table.exists</code>? How can I make sure they have migrated the table successfully?</p>