2 kwargs unused in 3 functions - `fca.py`

[jGaboardi]

Two keyword arguments not actually being used in three functions in fca.py.

• keyword arguments
  • supply_index="geoid"
  • normalize=False
• functions
  • fca_ratio()
  • two_stage_fca()
  • three_stage_fca()

see #78

[jGaboardi]

supply_index="geoid"

xref #25