Schema for data in CollectorUpdate.

def schema_complete():
        """Schema for data in CollectorUpdate."""
        return Schema({
            'stage': And(str, len),
            'timestamp': int,
            'status': And(str, lambda s: s in ['started', 'succeeded', 'failed']),
            # optional matrix
            Optional('matrix', default='default'): And(str, len),
            # optional information
            Optional('information', default={}): {
                Optional(Regex(r'([a-z][_a-z]*)')): object
            }
        })