Update phpunit path

Author: narendravaghela

.travis.yml

@@ -28,7 +28,7 @@ before_script:
   - set +H
 
 script:
-  - sh -c "if [ '$DEFAULT' = '1' ]; then phpunit --stderr; fi"
+  - sh -c "if [ '$DEFAULT' = '1' ]; then ./vendor/bin/phpunit --stderr; fi"
 
   - sh -c "if [ '$PHPCS' = '1' ]; then ./vendor/bin/phpcs -n -p --extensions=php --standard=vendor/cakephp/cakephp-codesniffer/CakePHP ./src ./tests; fi"