Fix 2 typos in the knife-spork post

* @nathenharvey's father misspelled his first name, it's "Nathen", not "Nathan"

* typo calling "`knife spork`" "`knife spark`" in the code sample bumping nagios
Merge pull request #1 from nathenharvey/patch-1

Fix 2 typos in the knife-spork post