fixed typo

missing "n" in unnecessary

Author: BlueChili

exercises/basic_every_some/problem.md

@@ -39,7 +39,7 @@ Use array#some and Array#every to check every user passed to your returned funct
 ## Conditions
 
 * Do not use any for/while loops or Array#forEach.
-* Do not create any unecessary functions e.g. helpers.
+* Do not create any unnecessary functions e.g. helpers.
 
 ## Resources