title: Can't migrate db rails, getting an error
body: <p>I am getting an error while migrating a database. The error is:</p>
  
  <pre><code>PG::UndefinedColumn: ERROR:  column roles.deleted_at does not exist
  LINE 1: SELECT "roles".* FROM "roles"  WHERE ("roles"."deleted_at" I...
                                                ^
  : SELECT "roles".* FROM "roles"  WHERE ("roles"."deleted_at" IS NULL)
  </code></pre>
  
  <p>Here is my  part of schema.rb:</p>
  
  <pre><code>create_table "roles", :force =&gt; true do |t|
  t.string   "name"
  t.string   "title"
  t.integer  "resource_id"
  t.string   "resource_type"
  t.datetime "created_at",    :null =&gt; false
  t.datetime "updated_at",    :null =&gt; false
  t.datetime "deleted_at"
  end
  </code></pre>
  
  <p>I tried to make:</p>
  
  <pre><code>rails generate migration AddDeletedAtToRoles deleted_at           
  </code></pre>
  
  <p>But it did not help.</p>