title: Configuring cascade delete with EF7
body: <p>I'm trying to configure a cascade delete using EF7 in a ASP.NET vNext application but I cannot find how to do it.</p>
  
  <p>I'm overriding <code>OnModelCreating</code> and I have this code:</p>
  
  <pre><code>  modelBuilder.Entity&lt;Category&gt;()
                .OneToMany&lt;Category&gt;( e =&gt; e.SubCategories )
                .ForeignKey( e =&gt; e.ParentCategoryId );
  </code></pre>
  
  <p>The generated migration looks like this:</p>
  
  <pre><code>    migrationBuilder.AddForeignKey("Category", "FK_Category_Category_ParentCategoryId", new[] { "ParentCategoryId" }, "Category", new[] { "Id" }, cascadeDelete: false);
  </code></pre>
  
  <p>Anyone know in what namespace the extensions to configure the cascade delete are defined?</p>
  
  <p>Thanks!</p>