Changed API version to 1.1

Twitter API version 1 is deprecated and so it was returning page not found error. So updated the version to 1.1. 
Regards,
Kishan
Updated for use with Twitter API version 1.1

The search endpoint is no longer a separate URI (https://dev.twitter.com/docs/api/1.1). Everything else seems to work as expected, as long as the user authenticates. I have tested this with almost all GET endpoints, but not for any POST endpoints.
Simplified API Version 1.1 Support
Merge branch 'master' of https://github.com/ksg91/twitter-async into pr-166
Updating about 1/2 of the unit tests for v1.1 of the API. #173 #161
Merge branch 'master' of github.com:jmathai/twitter-async