title: I grails migration plugin dbm-update saying "validation error"
body: <p>I have a hand written migration.<br>
  when I try to run it as:</p>
  
  <pre><code>grails dbm-update
  </code></pre>
  
  <p>I am getting this error:  </p>
  
  <pre><code>validation Error
  </code></pre>
  
  <p><strong>database-migration version:1.3.8</strong></p>
  
  <p><em>How can I run the migration plugin to be more verbose with the error message?</em></p>
  
  <p>Update:<br>
  I just tried to run the app and get this error</p>
  
  <pre><code>columnDataType is required, 093-add-Type-field.groovy::1418895018124-1::authorName (generated)::(Checksum: 3:81d125287730881fdb5d52cdbd198f68)
  </code></pre>
  
  <p>but I have defined the data type: </p>
  
  <pre><code>    column(name: "type", type: "varchar(255)") {
                      constraints(nullable: "true")
                  }
  .
  .
  addNotNullContraint(tableName: "tableName",columnName:"type");
  </code></pre>