[WIP] Add advanced plotting recipies

[mmikhasenko]

trafficstars

Closes #126

New Plots.jl recipe makes it easy to plot a curve over a histogram. There are two new functionality:

• plot(model::Function, WithData(h)): to adjust normalization of the model taking into account the bin width

• curvedfitwithpulls(h, best_model): a plot recipe for the histogram, model curve and pulls.

• [ ] Tests are passing

• [ ] Documentation is updated