Update endpoints.py
Update endpoints.py

Added endpoint for statuses/lookup (https://dev.twitter.com/docs/api/1.1/get/statuses/lookup).
fibears/twython,vivek8943/twython,Hasimir/twython,ping/twython,joebos/twython,ryanmcgrath/twython,Devyani-Divs/twython,Oire/twython,Fueled/twython,akarambir/twython