Fix winik states

[ThomasThelen]

When a winik's state is a written, it's written as a tibble. See here for reference. It turns out, some of the values may be null, which tibble won't handle and R won't throw an error (even though the tibble is never created).

Figure out of to fix this.

[zizroc]

i should be able to fix this. i'll look.

[ThomasThelen]

Looking forward to seeing how this works!