Fixed base test class

tests/src/Kernel/SmartlingTestBase.php

@@ -10,7 +10,7 @@ use Smartling\File\FileApi;
 /**
  * Smartling kernel test base class.
  */
-class SmartlingTestBase extends TMGMTKernelTestBase {
+abstract class SmartlingTestBase extends TMGMTKernelTestBase {
 
   public static $modules = ['tmgmt_smartling', 'tmgmt_extension_suit', 'tmgmt_file', 'file'];