Merge pull request #22 from arthurdarcet/master

Throw InvalidArgumentException when calling findOne{,OrFail} with invalid argument
Remove php_analyzer from scrutinizer (as ext-mongo is not installed)
Add Auth classes
Merge pull request #23 from julien-c/auth

Add Auth classes
Mention new auth feature in the README
Backport Reaaad/reaaad@23f6dffbe534e9d0de3719fe62140de949ecccaa
Bugfix: repair the Model::textSearch method