[Repository] add OperationInterface for repositories #3
[Repository] change QueryableInterface to use OperationInterface for repositories #3
[Repository] add CriteriaBuilderInterface #3
[Entity] remove QuerizeableInterface (use CriteriaBuilderInterface instead) #3
[Operation] add OperationInterface
[Entity] change OperationInterface to extend \PHPMentors\DomainKata\Operation\OperationInterface
[Repository] change OperationInterface to extend \PHPMentors\DomainKata\Operation\OperationInterface