UserRepository refactored into repositories

src/main/java/hdm/mi/growbros/models/user/UserRepository.java → src/main/java/hdm/mi/growbros/repositories/UserRepository.java

-package hdm.mi.growbros.models.user;
+package hdm.mi.growbros.repositories;
 
+import hdm.mi.growbros.models.user.User;
 import org.springframework.data.jpa.repository.JpaRepository;
 
 import java.util.Optional;