Some evernote coding challenges from:
https://evernote.com/careers/challenge.php

Signed-off-by: Vidhoon Viswanathan <vidhu2366@gmail.com>
Circular buffer

Signed-off-by: Vidhoon Viswanathan <vidhu2366@gmail.com>
ReadME added

Signed-off-by: Vidhoon Viswanathan <vidhu2366@gmail.com>