Fix chooseBestLanguage

That fixes when browser have more then one of app available language, that was choosen the prefered app language, instead of browser first (prefered) language.

Improved docs and remove Negotiator.

v0.2.0

add travis php 7

v0.1.2

tests of the service provider.

Testing more methods.

v0.1.1

Testing more cases and remove mock from translator.

v0.1.0

Change namespace and using the Negotiation\LanguageNegotiator class.

v0.0.1

add tree of lang files