//Finds the ship with a right name and removes it from ships_ vector
void Galaxy::removeShip(std::shared_ptr<Common::Ship> ship){
    if (!ships_.empty()){
        for (auto &i : ships_){
            std::shared_ptr<Common::Ship> temp = ships_[i];
            if ( temp->getName() == ship->getName())
            {
                ships_.erase(i);
                return;
            }
        }
    }
    throw( Common::StateException("Ship does not exist. Can not be removed."));
}