First draft to fix a bug when patching timeline events with extreme timestamp

[longd3]

• @spencerv discovered https://trello.com/c/GWSHI0ZW/32-provide-better-error-message-to-explain-that-you-can-t-update-the-wake-event-to-before-you-went-to-sleep , cc @jimmymlu
• Bug Summary: In feedback feature, patching a timeline event with extreme timestamps (for example future ts) return bad timeline because of a failure to validate the patch request.
• There are 2 validation processes. A> Feedback validations (to check if the input time make senses and doesn't break events order) and B> Timeline validations (to verify if the patched timeline meet sanity requirements)
• This PR adds another validation to process B to enforce such that the patched timeline have total sleep duration GTE 120 minues (please advise if you think otherwise). But after discussing with @pims, we agree that more rigid checks need to be added to process A
• @benejoseph: would you mind look at process A and advise the least intrusive way to handle that.

[pims]

As discussed, this is only "fixing" by throwing an exception and not returning the timeline.
Let's make sure we don't accept invalid input to prevent this from happening.