Add the information of a gene

            This adds a gene dict to variant['genes']

            Args:
                gene (dict): A gene dictionary

def add_gene(self, gene):
        """Add the information of a gene

            This adds a gene dict to variant['genes']

            Args:
                gene (dict): A gene dictionary

        """
        logger.debug("Adding gene {0} to variant {1}".format(
            gene, self['variant_id']))
        self['genes'].append(gene)