Updated .travis.yml

Author: creocoder

.travis.yml

@@ -15,7 +15,7 @@ before_script:
   - mysql -e 'create database yii2_nested_sets_test;'
 
 script:
-  - phpunit --coverage-clover=coverage.clover
+  - vendor/bin/phpunit --coverage-clover=coverage.clover
 
 after_script:
   - wget https://scrutinizer-ci.com/ocular.phar