Code review comment for lp://staging/~brendan-donegan/checkbox/story808_estimated_duration

It's a pretty simple change and tests revealed nothing breaks. Additional fields used to break the old message-passing protocol, but since that's no longer in use, this doesn't seem to be an issue.

Do keep in mind that at the moment, estimated_duration is limited to an integer. The data type can be changed later if desired, but do expect breakage if whatever is in that field can't be parsed into an integer.

Thanks!