Composer update is failing. See more details below.

php composer.phar update --prefer-dist

Problem 1
- ezsystems/behatbundle v5.4.0-rc1 requires ezsystems/ezpublish-kernel
~5.4@rc -> no matching package found.
- ezsystems/behatbundle v5.4.0-beta2 requires phpunit/phpunit
~4.0 -> no matching package found.
- ezsystems/behatbundle v5.4.0-beta1 requires ezsystems/ezpublish-kernel
~5.4@beta -> no matching package found.
- ezsystems/behatbundle dev-master requires phpunit/phpunit
~4.0 -> no matching package found.
- ezsystems/behatbundle 5.4.x-dev requires phpunit/phpunit
~4.0 -> no matching package found.
- Installation request for ezsystems/behatbundle @dev -> satisfiable by
ezsystems/behatbundle[5.4.x-dev, dev-master, v5.4.0-beta1, v5.4.0-beta2, v5.4.0-rc1].

Potential causes:
- A typo in the package name
- The package is not available in a stable-enough version according to your minimum-stability setting.
See <https://groups.google.com/d/topic/composer-dev/_g3ASeIFlrc/discussion> for more details.

Read <http://getcomposer.org/doc/articles/troubleshooting.md> for further common problems.