Create a new issue link type.
        :param outward:
        :param inward:
        :param link_type_name:
        :return:

def create_issue_link_type(self, link_type_name, inward, outward):
        """Create a new issue link type.
        :param outward:
        :param inward:
        :param link_type_name:
        :return:
        """
        if link_type_name.lower() in [x.lower() for x in self.get_issue_link_types_names()]:
            log.error("Link type name already exists")
            return "Link type name already exists"
        data = {
            'name': link_type_name,
            'inward': inward,
            'outward': outward
        }
        return self.create_issue_link_type_by_json(data=data)