Disable showing accuracy feedback
After reading the paper drafted by @ithacker, it is clear that the kind of feedback we're giving on accuracy of estimates is counter-productive: it pushes the participant to be overly concerned with whether they are getting the numbers right. Until we have more qualitative, illustrative feedback, I think it is better to just show the raw numbers.
This hides the bar indicating how accurate the estimate was.
Stop-gap until #26 is implemented.