Update GroupRepositoryTest.php

Simple CS fix: Removed double empty space.

Author: phoenix128

app/code/Magento/Customer/Test/Unit/Model/ResourceModel/GroupRepositoryTest.php

@@ -202,8 +202,7 @@ public function testSave()
         $this->groupModel->expects($this->atLeastOnce())
             ->method('getTaxClassName')
             ->willReturn('Tax class name');
-        
-        
+
         $this->factoryCreatedGroup->expects($this->once())
             ->method('setId')
             ->with($groupId)