Fixed test setting.

.travis.yml

@@ -39,6 +39,7 @@ addons:
 
 install:
   - composer self-update && composer --version
+  - composer global require "fxp/composer-asset-plugin:~1.0"
   - export PATH="$HOME/.composer/vendor/bin:$PATH"
 # core framework:
   - composer install --prefer-dist