Improve error message for static test for redundant dependencies (#224)

Author: bl4de

dev/tests/static/testsuite/Magento/Test/Integrity/DependencyTest.php

@@ -59,6 +59,12 @@ class DependencyTest extends \PHPUnit\Framework\TestCase
      */
     public const MAP_TYPE_REDUNDANT = 'redundant';
 
+    /**
+     * Redundant dependencies error message
+     */
+    public const UNUSED_DEPENDENCY_ERROR_MSG =
+        'Some dependencies required by composer.json are not used in the module and must be removed:';
+
     /**
      * Count of directories in path
      */
@@ -869,7 +875,7 @@ public function testRedundant()
             }
         }
         if (!empty($output)) {
-            $this->fail("Redundant dependencies found!\r\n" . implode(' ', $output));
+            $this->fail(self::UNUSED_DEPENDENCY_ERROR_MSG . "\r\n" . implode(' ', $output));
         }
     }