Use assertStringContainsString for asserting strings

Author: Naktibalda

tests/unit/Codeception/Module/PhpBrowserTest.php

@@ -557,7 +557,7 @@ public function testRequestApi()
  $data = data::get('form');
  $this->assertEquals('davert', $data['user']);
  $this->assertInternalType('string', $response);
- $this->assertContains('Welcome to test app', $response);
+ $this->assertStringContainsString('Welcome to test app', $response);
  $this->module->click('Welcome to test app'); // page not loaded
  }