initial 40% with funding raised

[mallick-prat]

• 40% initial tax rate
• Abolition of 3 benefits: SSI, WIC, SNAP
  To-do:
• Parametric Age-based UBI reform: https://github.com/PolicyEngine/openfisca-us/blob/master/openfisca_us/parameters/contrib/ubi_center/basic_income/amount_by_age.yaml

[nikhilwoodruff]

Looks great!

• Tidy up notebook a bit
• Add key funding numbers to a table in the notebook
• Add function to show the decile chart (optional)