Add compose require ramsey/uuid into travis.yml

Author: terox

.travis.yml

@@ -29,6 +29,7 @@ install:
   - if [ "$DEPENDENCIES" == "dev" ]; then perl -pi -e 's/^}$/,"minimum-stability":"dev"}/' composer.json; fi;
   - if [ "$DEPENDENCIES" != "low" ]; then composer update; fi;
   - if [ "$DEPENDENCIES" == "low" ]; then composer update --prefer-lowest; fi;
+  - composer require ramsey/uuid
 
 before_script:
   - echo "<?php if (PHP_VERSION_ID >= 50400) echo ',@php5.4';" > php_version_tags.php