Major change , changed organized_tweets schema

* Removed trend id column from organized_tweets
* added trend and location_id to the same table
* This helps in querying faster as it avoids joins and the addition of
* columns is not space consuming
* Modified the update_organized_tweets method to add values to these
* column
Query that computes TFIDF :beers:

* This query takes location id and trend name to generate the tfidf
* value for the entities that belong to the the trend