removing findBySlug from the Sluggable behavior

It is now generated automatically with all the fields findBy<Field> methods
Merge remote-tracking branch 'daniel/master' into findby

Conflicts:
	src/Mongator/Behavior/Sluggable.php
proper version for mongator dependency
Added Identifiable behaviour
Added Identifiable behaviour
self.version
Update composer.json
Update composer.json
Update composer.json
Update 08_identifiable.md
Update README.md
composer
Merge pull request #9 from dripolles/master

Removing Archive static use from tests
improved Sluggable code, now use Twig
sluggable tamplete
new feature global Sluggable models
minor fix
new Stringifiable method
documentation
added fromToString to Sluggable behavior