Create Lucky Sevens

I banged out the entire assignment in 1 day. It was not that difficult except figuring out how to do correct "slice sizes" in python. It is good to remember that the "slice index" is not included in the actual slice and so must be augmented.

If an addendum or revision is made to this code, it will be to take the user's argument a function because it can potentially happen a great many times. I will probably be using the slice search function a great many times, to the point where I might make it a library to be loaded later.