Trigger errors on deprecated fixture formats.

Update fixtures in tests. Instead of adding shims, Jose and I have
decided it is better to provide features in the UpgradeShell to migrate
fixtures. Fixtures will now trigger errors on known to be old formats.

lib/Cake/Test/TestCase/TestSuite/TestFixtureTest.php

@@ -41,7 +41,7 @@ class ArticleFixture extends TestFixture {
  * @var array
  */
 	public $fields = [
-		'id' => ['type' => 'integer', 'key' => 'primary'],
+		'id' => ['type' => 'integer'],
 		'name' => ['type' => 'string', 'length' => '255'],
 		'created' => ['type' => 'datetime'],
 		'constraints' => [
@@ -82,7 +82,7 @@ class StringsTestFixture extends TestFixture {
  * @var array
  */
 	public $fields = array(
-		'id' => array('type' => 'integer', 'key' => 'primary'),
+		'id' => array('type' => 'integer'),
 		'name' => array('type' => 'string', 'length' => '255'),
 		'email' => array('type' => 'string', 'length' => '255'),
 		'age' => array('type' => 'integer', 'default' => 10)

lib/Cake/TestSuite/Fixture/TestFixture.php

@@ -147,8 +147,11 @@ protected function _schemaFromFields() {
 			if ($field === 'constraints' || $field === 'indexes') {
 				continue;
 			}
-			// TODO issue E_USER_NOTICE if a column defines 'key'?
-			// Or handle the case correctly?
+			// Trigger errors on deprecated usage.
+			if (is_array($data) && isset($data['key'])) {
+				$msg = __d('cake_dev', 'Usage of the `key` options in columns is not supported. Try using the upgrade shell to migrate your fixtures.`');
+				trigger_error($msg, E_USER_NOTICE);
+			}
 			$this->_schema->addColumn($field, $data);
 		}
 		if (!empty($this->fields['constraints'])) {
@@ -157,8 +160,11 @@ protected function _schemaFromFields() {
 			}
 		}
 		if (!empty($this->fields['indexes'])) {
-			// TODO 2.x indexes contains indexes + constraints.
-			// Should we issue an error or handle the case?
+			// Trigger errors on deprecated usage.
+			if (empty($data['type'])) {
+				$msg = __d('cake_dev', 'Indexes must define a type. Try using the upgrade shell to migrate your fixtures.');
+				trigger_error($msg, E_USER_NOTICE);
+			}
 			foreach ($this->fields['indexes'] as $name => $data) {
 				$this->_schema->addIndex($name, $data);
 			}