Upgrade dependencies.

Fix https://github.com/openl10n/openl10n-sdk/pull/7

* symfony/filesystem (v2.5.1 => v2.5.2)
* symfony/config (v2.5.1 => v2.5.2)
* symfony/console (v2.5.1 => v2.5.2)
* symfony/event-dispatcher (v2.5.1 => v2.5.2)
* symfony/dependency-injection (v2.5.1 => v2.5.2)
* symfony/finder (v2.5.1 => v2.5.2)
* symfony/yaml (v2.5.1 => v2.5.2)
* guzzlehttp/streams (1.1.0 => 1.4.0)
* guzzlehttp/guzzle (4.1.2 => 4.1.4)
* openl10n/sdk (9fda6cb => cb679a1)