Integer bins via rounding

Just a first pass at doing integer binning via rounding the edges and passing those into the histogram function. In a situation like [25, 81], this will result in 10 bins with a per-bin width of either 5 or 6. If people aren't fans of this, that's totally fine.

I assume I'm doing plenty wrong, too. Please tear me apart!
(Also, just in case it seems like I'm contradicting myself, I absolutely said yesterday that was I seeing NaNs -- but the NaNs I saw were nulls at this stage, I believe :p)