Changing b discriminator: CSVv2 to DeepFlav (deepjet)

[jeongsumin]

As we know about b discriminator, DeepFlavour (Deepjet) is more efficient than CSVv2.
So I check the result when using the deepflavour discriminator.

First, there was no problem when I modified about btagWeightproducer (in TZWi) and btagSFproducer (in nanoAODTools).

But you need to change the btagSFproducer.py when produce the ntuple with deepflavour discriminator:

1. line 35) change the algo='csvv2' -> algo='deepjet' & selectedWPs=['M', 'shape_corr'] -> selectedWPs=['L', 'shape_corr']
2. after line 325) adding the new lambda function "btagSFLegacy2016" because key of deepjet for 2016 name is "Legacy2016"