Add new type challenge based on scala's tupled function

[stewartHutchins]

I was playing with Python the other day, I tried to implement Scala's "tupled" function.

I thought it had some potential to make a good type challenge.

I think the TODO comment at the top might need some additional clarification.

[stewartHutchins]

I have just noticed that adding a return type to the function signature is optional - I imagine this is a problem :/ as such I'm converting this to a draft