fix travis build

#23 and #24 both see build failures unrelated to their changes. lets see if this fixes it.
so since 2.6, changing the request locale at this late stage does not affect the translation component anymore. i would leave this as a testing artifact. in real use cases, you either get the right locale from the request already, or set it in a request listener, or explicitly ask for it in the call to the translator.

if an application really did like this test, its a symfony BC question that has no relation to this bundle as far as i can tell. or do we do something about this that stops working? i checked our code and did not find anything that suggests we do something for this.