Parse Transformer returning a tuple rather than dict

[e-lo]

CubeTransformer().transform(parse_tree) is returning a singleton tuple.

Expecting a dict.

cc: Issue found by @DavidOry

[e-lo]

Issue because it will return a tuple if it finds the program type line, and a plain dictionary if not. Can be fixed by checking type first. Standby.

TRANSIT_LINE_FILE_GRAMMAR = r"""
?start             : program_type_line? lines