Finalized MergeTwoOmbdEntryLists

Gotta say, writing these feels pretty boring, but I'm assuming that once
they fail, if we ever change their code again, it'll pay off, right?

I just don't know if the tests I'm writing are even any good or not. Like
the things I'm currently writing have no tests yet because I haven't
finalized what exactly I want to do with those methods. I feel like I
should be doing more of the TDD stuff, writing tests that fails, then
write the code that'll pass the tests, but I'm not sure that that's what's
best for me right now, because that seems like it'd require a good deal of
forethought.

Maybe on my next method.