title: Cassandra phantom-dsl derived column is missing in create database generated queries
body: <p>I have following table definition</p>
  
  <pre><code>import com.outworkers.phantom.builder.primitives.Primitive
  import com.outworkers.phantom.dsl._
  
  abstract class DST[V, P &lt;: TSP[V], T &lt;: DST[V, P, T]] extends Table[T, P] {
    object entityKey extends StringColumn with PartitionKey {
      override lazy val name = "entity_key"
    }
  
   abstract class entityValue(implicit ev: Primitive[V]) extends PrimitiveColumn[V] {
      override lazy val name = "entity_value"
    }
  </code></pre>
  
  <p>In concrete table sub class</p>
  
  <pre><code>abstract class SDST[P &lt;: TSP[String]] extends DST[String, P, SDST[P]] {
    override def tableName: String = "\"SDS\""
  
    object entityValue extends entityValue
  }
  </code></pre>
  
  <p>Database class</p>
  
  <pre><code>class TestDatabase(override val connector: CassandraConnection) extends Database[TestDatabase](connector) {
  object SDST extends SDST[SDSR] with connector.Connector {
      override def fromRow(r: Row): SDSR=
        SDSR(entityKey(r), entityValue(r))
   }
  }
  </code></pre>
  
  <p>The create table query generated by phantom-dsl looks like below</p>
  
  <p>database.create()</p>
  
  <pre><code>c.o.phantom Executing query: CREATE TABLE IF NOT EXISTS test."SDS" (entity_key text,PRIMARY KEY (entity_key))
  </code></pre>
  
  <p>As you can see derived column is missing from the create table DDL.</p>
  
  <p>Please let me know if I am missing something in the implementation.</p>
  
  <p>Omitted class definitions like SDSR and TSP are simple case classes. </p>
  
  <p>Thanks</p>