0.8.0: Merge pull request #1260 from martinholmer/tcio-error-msg

Contributor	PR#	Description
Anderson Frailey	#1235	Add ability to calculate, and possibly tax, UBI benefits
Anderson Frailey	#1247	Add additional deduction and credit haircut policy parameters
Matt Jensen	#1247	Add constant charitable giving elasticities to behavioral response
Anderson Frailey	#1252	Add another credit haircut policy parameter
Martin Holmer	#1253	Make Tax-Calculator CLI an entry point to the taxcalc package
Martin Holmer	#1258	Add --tables option to Tax-Calculator CLI