Still build a User even if no api is passed in
Merge pull request #351 from tewalds/model_api

Still build a User even if no api is passed in
Reconnect according to twitters recommendations.

Recommendations found here: https://dev.twitter.com/docs/streaming-apis/connecting#Reconnecting

A simpler and more complete version of
- https://github.com/tweepy/tweepy/pull/132
- https://github.com/tweepy/tweepy/pull/150
only handling the reconnect strategies.