Find task classes from category.namespace.name strings
        tasks - list of strings

def setup_tasks(self, tasks):
        """
        Find task classes from category.namespace.name strings
        tasks - list of strings
        """
        task_classes = []
        for task in tasks:
            category, namespace, name = task.split(".")
            try:
                cls = find_in_registry(category=category, namespace=namespace, name=name)[0]
            except TypeError:
                log.error("Could not find the task with category.namespace.name {0}".format(task))
                raise TypeError
            task_classes.append(cls)
        self.tasks = task_classes