Project 2: mob detection algorithm adjustments

[sockeqwe]

Form clusters by the number of users and not by the number of tweets

[sacdallago]

@sockeqwe good observation! Retweets though are also other users, but the same tweet. It might even be that a retweet is more important than a real tweet!
Anyway maybe it makes sense to write a very easy function that gives different weights to retweets, original tweets, mentions, answers, aso

[phdowling]

see #9