EmotionAll MVP

Users can choose from a list of trends in our database and see a heat map of the world based on the sentiment of tweets for that particular trend. 
This model is really mixing two different concerns: 1) Storing Trends in the database and perhaps their associated tweets and 2) Getting tweets for trends from the twitter API.

These two concerns should be separated.  The ActiveRecord model should handle the database and associations and some scopes (ordering etc).

Then you can create a "service object" (Take a lot at [#2 in this article](http://blog.codeclimate.com/blog/2012/10/17/7-ways-to-decompose-fat-activerecord-models/)).

The object might be `TwitterTrends` with methods such as `current_trends`, `tweets` (and then the `Tweet` model should be able to store those tweets in its own table or maybe you'd have a method to do that), `update` (which would call `Trend.most_recent_tweets`) etc.