Update quotes.txt

Change-Id: I6e82dbd4a38e91e43498f009a2cb0ac7fe630879
GitHub-Last-Rev: 6f69329187
GitHub-Pull-Request: golang/scratch#11
Reviewed-on: https://go-review.googlesource.com/91175
Reviewed-by: Andrew Bonventre <andybons@golang.org>

andybons/quotes.txt

@@ -1 +1,2 @@
 “The two most important days in your life are the day you are born and the day you find out why.”
+“Computers are useless. They can only give you answers.” Pablo Picasso