Add min and maximum argumet.

[talwrii]

Min and maximum arguments - kind of similar to another pull request - but deals with edge cases a little better and doesn't use environment variables.

[holman]

Going to go with #54 instead here.

[sindresorhus]

@holman to quote you in #54:

Not a huge fan of using environment variables here

Can you reconsider this instead? Using flags would be a more natural solution here.
Though --min/--max instead of -m/-M would be better.

[davidcelis]

I'd also ask for reconsideration here; If the environment variable solution had array issues, perhaps this could be revisited?

[holman]

I'm mostly just not into the additional code that comes with it.

[davidcelis]

That's fair; thanks for the honesty. In the meantime, if anybody else needs this for some utility like I did, I brought in @talwrii's changes into my own fork and added a homebrew formula to install it. brew tap davidcelis/spark && brew install davidcelis/spark/spark