Fix travis CI tests running.

Author: GhaziTriki

.travis.yml

@@ -31,8 +31,8 @@ before_script:
 
 script:
   - mkdir -p build/logs
-  - if [ "$TRAVIS_PHP_VERSION" != "nightly" ]; then phpunit --coverage-clover build/logs/clover.xml; fi
-  - if [ "$TRAVIS_PHP_VERSION" == "nightly" ]; then phpunit; fi
+  - if [ "$TRAVIS_PHP_VERSION" != "nightly" ]; then vendor/bin/phpunit --coverage-clover build/logs/clover.xml; fi
+  - if [ "$TRAVIS_PHP_VERSION" == "nightly" ]; then vendor/bin/phpunit; fi
 
 after_script:
   - if [ "$TRAVIS_PHP_VERSION" == "7.0" ] || [ "$TRAVIS_PHP_VERSION" == "7.1" ] || [ "$TRAVIS_PHP_VERSION" == "7.2" ]; then php vendor/bin/php-coveralls -v; fi