title: What is :cascade in rails schema.rb and where did it come from?
body: <p>After adding another migration and occasional decision to drop and migrate I checked my schema.rb
  and saw this</p>
  
  <pre><code>create_table "users", force: :cascade do |t|
  </code></pre>
  
  <p>I haven't committed this changes yet and on remote I have this</p>
  
  <pre><code>create_table "users", force: true do |t|
  </code></pre>
  
  <p>Now I have cascade in front of each table. What is cascade and where did it come from?</p>