v1.5.0: A better estimation of Shapley values with ACV backend

Features

• New backend added to Shapash : ACV (#245)
  • New backend parameter on the compile method on which we can select 'acv'
  • New tutorial to illustrate how to work with Shapash and ACV
  • More info about ACV here : https://github.com/salimamoukou/acv00
• lightgbm added to Shapash accepted list of models (#232)

Bug fixes

• Fix Shapash Report bug when using multiclass (#223)
• Fix an attribute in SmartExplainer object (#247)