PredictTheNumber - bugfix (really)
Looks like I just shifted the bug with the last commit.
Turns out I was looking at the problem space slightly wrong. (it happens and is one of the dangers of doing some problems with recursion)

Solution seems logically sound (I just spent the last hour testing it on paper) and the bug should be well and truly squashed now.

Integration tested for strings of length 1-32, which should be ample length to catch any problems.

All tests green.