Parser allows some args in function calls to not have comma separation.

[philkuz]

Just wanted to make you aware that the parser allows some function args to be declared without comma separation.

For example, the parser does not error out for the following queries and returns the same ast as if the first comma was not missing.

json('test' cool_kwarg='test')
json(other_kwarg='test' cool_kwarg='cool')
json(other_kwarg='test' cool_kwarg='cool', cooler_kwarg='nah')

All of which should have a comma after the first arg.

However, these calls fail:
json(other_kwarg='test' cool_kwarg='cool' cooler_kwarg='nah')
json('test' cool_kwarg='cool' cooler_kwarg='nah')