Initial version of #merge works

It is the simplest thing that could possibly work. Need to add
more test cases to drive out the behavior.
Merge arrays where the right is smaller than the left

Can now handle the case where the element in the array in the right
is smaller than the element in the array that is considered the "left."

It is still a naive solution -- TDD will drive out the rest of the
behavior so that as the tests become more specific, the production code
becomes more generic. (paraprhasing Uncle Bob Martin)