Pull phpunit 5.7

Signed-off-by: Christoph Wurst <christoph@winzerhof-wurst.at>

.travis.yml

@@ -38,6 +38,10 @@ cache:
 
 before_install:
   - php --info
+  # Download phpunit 5.7
+  - wget https://phar.phpunit.de/phpunit-5.7.phar -O phpunit
+  - chmod u+x phpunit
+
   # XDebug is only needed if we report coverage -> speeds up other builds
   - if [[ "$PHP_COVERAGE" = "FALSE" ]]; then phpenv config-rm xdebug.ini; fi
 
@@ -74,7 +78,7 @@ script:
 
   # Run PHP tests
   - cd tests
-  - phpunit --configuration phpunit.xml
+  - ../phpunit --configuration phpunit.xml
 
   # Publish PHP coverage to scrutinizer
   - if [[ "$PHP_COVERAGE" = "TRUE" ]]; then wget https://scrutinizer-ci.com/ocular.phar; fi