corrected phpunit.xml path in .gitlab-ci.yml

Author: Raaghu

.gitlab-ci.yml

@@ -4,32 +4,32 @@ before_script:
 test_5.4:
   image : phpplatform/php-apache-xdebug-composer:5.4
   script :
-    - ./vendor/bin/phpunit -c ci/phpunit.xml
+    - ./vendor/bin/phpunit -c phpunit.xml
 
 test_5.5:
   image : phpplatform/php-apache-xdebug-composer:5.5
   script :
-    - ./vendor/bin/phpunit -c ci/phpunit.xml
+    - ./vendor/bin/phpunit -c phpunit.xml
 
 test_5.6:
   image : phpplatform/php-apache-xdebug-composer:5.6
   script :
-    - ./vendor/bin/phpunit -c ci/phpunit.xml
+    - ./vendor/bin/phpunit -c phpunit.xml
 
 test_7.0:
   image : phpplatform/php-apache-xdebug-composer:7.0
   script :
-    - ./vendor/bin/phpunit -c ci/phpunit.xml
+    - ./vendor/bin/phpunit -c phpunit.xml
 
 test_7.1:
   image : phpplatform/php-apache-xdebug-composer:7.1
   script :
-    - ./vendor/bin/phpunit -c ci/phpunit.xml
+    - ./vendor/bin/phpunit -c phpunit.xml
 
 test_7.2:
   image : phpplatform/php-apache-xdebug-composer:7.2
   script :
-    - ./vendor/bin/phpunit -c ci/phpunit.xml
+    - ./vendor/bin/phpunit -c phpunit.xml
 
 after_script:
   - bash <(curl -s https://codecov.io/bash) -t c09c03aa-44ab-4b07-934e-f20fd3a604c1