Fixed random words function to correctly uppercase words

Author: tongrhj

exercises/randomizer.js

@@ -33,7 +33,7 @@ function randomWords(count, options) {
   var result = loremIpsum().split(' ').slice(0, count)
   if (options.capitalized) {
     result = result.map(function(word) {
-      word[0] = word[0].toUpperCase()
+      word = word[0].toUpperCase() + word.subString(0)
       return word
     })
   }