Fatal error: Cannot use Drupal\webform\Entity\Webform as Webform

Hi Jacob,
Thanks for your great work in webform.

I tried to install the latest dev version and I got the following error:
Note:I tried to revert to Version: 8.x-5.0-beta9+19-dev and it worked fine, I'm running PHP 7.0.10

( ! ) Fatal error: Cannot use Drupal\webform\Entity\Webform as Webform because the name is already in use in C:\wamp64\www\drupal-8.2.6\modules\webform\src\Element\WebformExcludedBase.php on line 7
Call Stack
#	Time	Memory	Function	Location
1	0.0000	365584	{main}( )	...\index.php:0
2	0.0160	1614584	Drupal\Core\DrupalKernel->handle( )	...\index.php:19
3	0.0580	3800384	Stack\StackedHttpKernel->handle( )	...\DrupalKernel.php:652
4	0.0580	3800384	Drupal\Core\StackMiddleware\NegotiationMiddleware->handle( )	...\StackedHttpKernel.php:23
5	0.0580	3800416	Drupal\Core\StackMiddleware\ReverseProxyMiddleware->handle( )	...\NegotiationMiddleware.php:50
6	0.0580	3800416	Drupal\page_cache\StackMiddleware\PageCache->handle( )	...\ReverseProxyMiddleware.php:47
7	0.0590	3803136	Drupal\page_cache\StackMiddleware\PageCache->pass( )	...\PageCache.php:78
8	0.0590	3803136	Drupal\Core\StackMiddleware\KernelPreHandle->handle( )	...\PageCache.php:99
9	0.1170	9807760	Drupal\Core\StackMiddleware\Session->handle( )	...\KernelPreHandle.php:47
10	0.3680	10176144	Symfony\Component\HttpKernel\HttpKernel->handle( )	...\Session.php:57
11	0.3680	10176560	Symfony\Component\HttpKernel\HttpKernel->handleRaw( )	...\HttpKernel.php:64
12	0.5910	15988400	call_user_func_array:{C:\wamp64\www\drupal-8.2.6\vendor\symfony\http-kernel\HttpKernel.php:144} ( )	...\HttpKernel.php:144
13	0.5910	15988464	Drupal\Core\EventSubscriber\EarlyRenderingControllerWrapperSubscriber->Drupal\Core\EventSubscriber\{closure}( )	...\HttpKernel.php:144
14	0.5910	15988464	Drupal\Core\EventSubscriber\EarlyRenderingControllerWrapperSubscriber->wrapControllerExecutionInRenderContext( )	...\EarlyRenderingControllerWrapperSubscriber.php:97
15	0.5920	15996000	Drupal\Core\Render\Renderer->executeInRenderContext( )	...\EarlyRenderingControllerWrapperSubscriber.php:124
16	0.5920	15996392	Drupal\Core\EventSubscriber\EarlyRenderingControllerWrapperSubscriber->Drupal\Core\EventSubscriber\{closure}( )	...\Renderer.php:574
17	0.5920	15996392	call_user_func_array:{C:\wamp64\www\drupal-8.2.6\core\lib\Drupal\Core\EventSubscriber\EarlyRenderingControllerWrapperSubscriber.php:123} ( )	...\EarlyRenderingControllerWrapperSubscriber.php:123
18	0.5920	15996800	Drupal\Core\Controller\FormController->getContentResult( )	...\EarlyRenderingControllerWrapperSubscriber.php:123
19	0.6010	16475384	Drupal\Core\Form\FormBuilder->buildForm( )	...\FormController.php:74
20	2.1611	21337776	Drupal\Core\Form\FormBuilder->prepareForm( )	...\FormBuilder.php:272
21	2.1621	21345256	Drupal\Core\Render\ElementInfoManager->getInfo( )	...\FormBuilder.php:794
22	2.1861	22077784	Drupal\Core\Render\ElementInfoManager->buildInfo( )	...\ElementInfoManager.php:76
23	2.4831	24034272	Drupal\Core\Render\ElementInfoManager->createInstance( )	...\ElementInfoManager.php:110
24	2.4831	24034328	Drupal\Component\Plugin\PluginManagerBase->createInstance( )	...\ElementInfoManager.php:140
25	2.4831	24034328	Drupal\Core\Plugin\Factory\ContainerFactory->createInstance( )	...\PluginManagerBase.php:84
26	2.4831	24034328	Drupal\Component\Plugin\Factory\DefaultFactory::getPluginClass( )	...\ContainerFactory.php:17
27	2.4831	24034648	class_exists ( )	...\DefaultFactory.php:96
28	2.4831	24034728	spl_autoload_call ( )	...\DefaultFactory.php:96
29	2.4831	24034888	Composer\Autoload\ClassLoader->loadClass( )	...\DefaultFactory.php:96
30	2.4831	24035000	Composer\Autoload\includeFile( )	...\ClassLoader.php:322
31	2.4831	24042920	include( 'C:\wamp64\www\drupal-8.2.6\modules\webform\src\Element\WebformExcludedColumns.php' )	...\ClassLoader.php:440
32	2.4831	24042920	spl_autoload_call ( )	...\WebformExcludedColumns.php:12
33	2.4831	24043080	Composer\Autoload\ClassLoader->loadClass( )	...\WebformExcludedColumns.php:12
34	2.4841	24043192	Composer\Autoload\includeFile( )

Thanks for your help