title: Can't insert new row in cakephp 3.0
body: <p>I am not able to insert a new row in table and getting the error</p>
  
  <blockquote>
    <p>2016-04-12 09:23:54 Error: [RuntimeException] Cannot insert row in
    "table_name" table, it has no primary key. Request URL:</p>
  </blockquote>
  
  <p>I am using ORM and my code given below</p>
  
  <pre><code>$entityTable = TableRegistry::get('TableName');
  $entity = $entityTable-&gt;newEntity();
  $entity-&gt;name = 'Test Name';
  $entity-&gt;image = 'test.png';
  $entity-&gt;type = 1;
  if($entityTable-&gt;save($entity)) {
      $this-&gt;Flash-&gt;success('Added successfully.');
  } else {
      $this-&gt;Flash-&gt;error('Error!.');
  } 
  </code></pre>
  
  <p>And my table is</p>
  
  <pre><code>CREATE TABLE `table_name` (
    `id` int(11) NOT NULL AUTO_INCREMENT,
    `name` varchar(255) COLLATE utf8_unicode_ci NOT NULL,
    `image` text COLLATE utf8_unicode_ci NOT NULL,
    `type` int(1) NOT NULL,
    PRIMARY KEY (`id`)
  ) ENGINE=MyISAM DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci AUTO_INCREMENT=1;
  </code></pre>