remove Null Transport

src/Transport/Factory.php

@@ -21,7 +21,6 @@ abstract class Factory
         'file'      => 'Zend\Mail\Transport\File',
         'inmemory'  => 'Zend\Mail\Transport\InMemory',
         'memory'    => 'Zend\Mail\Transport\InMemory',
-        'null'      => 'Zend\Mail\Transport\InMemory',
         'sendmail'  => 'Zend\Mail\Transport\Sendmail',
         'smtp'      => 'Zend\Mail\Transport\Smtp',
     ];

test/Transport/FactoryTest.php

@@ -71,10 +71,6 @@ public function typeProvider()
             ['Zend\Mail\Transport\Smtp'],
         ];
 
-        if (version_compare(PHP_VERSION, '7.0', '<')) {
-            $types[] = ['Zend\Mail\Transport\Null'];
-        }
-
         return $types;
     }
 
@@ -96,15 +92,12 @@ public function typeAliasProvider()
     {
         return [
             ['file', 'Zend\Mail\Transport\File'],
-            ['null', 'Zend\Mail\Transport\InMemory'],
             ['memory', 'Zend\Mail\Transport\InMemory'],
             ['inmemory', 'Zend\Mail\Transport\InMemory'],
             ['InMemory', 'Zend\Mail\Transport\InMemory'],
             ['sendmail', 'Zend\Mail\Transport\Sendmail'],
             ['smtp', 'Zend\Mail\Transport\Smtp'],
             ['File', 'Zend\Mail\Transport\File'],
-            ['Null', 'Zend\Mail\Transport\InMemory'],
-            ['NULL', 'Zend\Mail\Transport\InMemory'],
             ['Sendmail', 'Zend\Mail\Transport\Sendmail'],
             ['SendMail', 'Zend\Mail\Transport\Sendmail'],
             ['Smtp', 'Zend\Mail\Transport\Smtp'],
@@ -118,7 +111,7 @@ public function typeAliasProvider()
     public function testCanUseTraversableAsSpec()
     {
         $spec = new ArrayObject([
-            'type' => 'null'
+            'type' => 'inMemory'
         ]);
 
         $transport = Factory::create($spec);