Handle null fields when summarizing

[stvnrlly]

Currently, the bot assumes that common fields will always be available for parsing, but that's not the case. Instead, the bot should ignore the field if it's null.

[mgwalker]

Do you have any more info on this one? I'm not sure what it's referring to and can only find one place where null kind of misbehaves. I'm guessing this got fixed incidentally when you did all the work on the interview.

[stvnrlly]

It might have been mostly fixed, but I did see this today. My previous standup was a simple "OOO" one, and the previous blocker was listed as null. That might be the sole remaining thing.