Add step in pipeline to calculate time since last tweet by user

[frhino]

We want to strip multiple counts by users posting repeatedly (diatribe)

[JGreenLowe]

I might be interested in working on this one! What exactly did you have in mind in terms of 'repeatedly'? Do you want to count a long rant with four tweets posted one after the other to exceed the 140-character limit as just one tweet? Or is it more about reducing the signal from users who show up every day and post the same kind of information about how the bus they commute on is running late again?