Merge pull request #176 from imwithsam/patch-1

Fix minor typo

exercises/hello-world/TUTORIAL.md

 much of what makes up the more valuable conversations on Exercism.
 
 For now, let's just take a quick review of our solution and see if there's
-any part of it we'd like to refactor.  Refactoring is changing the the way
+any part of it we'd like to refactor.  Refactoring is changing the way
 a bit of code reads without changing what it does.
 
 Right now, the details of detecting whether the caller of `hello()` has