Remove calls to getMockForAbstractClass()

Author: alexandre-daubois

Tests/DelegatingEngineTest.php

@@ -133,7 +133,7 @@ private function getEngineMock($template, $supports)
 
  private function getStreamingEngineMock($template, $supports)
  {
- $engine = $this->getMockForAbstractClass(MyStreamingEngine::class);
+ $engine = $this->createMock(MyStreamingEngine::class);
 
  $engine->expects($this->once())
  ->method('supports')