Release notes for next taxcalc release

[jdebacker]

I think we are due to have a new release of the taxcalc package. Please post updates for the release notes here. I'll keep a list of unique additions in this comment.

API Changes

New Features

• Package available for Python 3.9 (Update to Python 3.9 #2522 by Max Ghenis)
• Parameters for QBI deduction phaseout (Add parameters for QBI deduction phaseout #2508 by Peter Metz)
• Allow interaction with calcfunctions.py functions and unit tests without @jit decorator (Allow for unit tests without decorators #2515 by Jacob Chuslo)

Bug Fixes

• Fix default parameter value for deduction for blind and aged widowed taxpayers -- does not affect results for puf.csv or cps.csv users. (Fix standard deduction for blind and aged #2537 by Jacob Chuslo)
• Include self-employment tax in calculation of partnership-specific marginal tax rates (MTR for partnership income #2486 by Cody Kallen)
• Fix stacking of an optional capital gains tax bracket (Modify base for top capital gains tax rate (CG_rt4) #2500 by Peter Metz)
• Fix bug caused by adjusting the indexed status of a parameter while also adjusting the parameter's value and a related parameter's value. (Fix related params #2532)

Also, changes to make compatible with latest versions of dependencies.

cc @MattHJensen @MaxGhenis @Peter-Metz @andersonfrailey @chusloj

edited to include comments from @MattHJensen

[MattHJensen]

@jdebacker, thanks a lot for putting this together. A few comments so far:

The API Changes section has been devoted to breaking changes in the past, so I believe #2515 should be under New Features instead.

I find it helpful to be a little more descriptive in bug fixes. Many only end up affecting a tiny slice of the user base, and it is nice for someone to know whether it affects them without worriedly clicking through to the PR. So, perhaps:

• Fix default parameter value for deduction for blind and aged widowed taxpayers.
• Include self-employment tax in calculation of partnership-specific marginal tax rates.
• Fix stacking of an optional capital gains tax bracket.

[hdoupe]

@jdebacker thanks for kicking this off:

• Fix bug caused by adjusting the indexed status of a parameter while also adjusting the parameter's value and a related parameter's value. (Fix related params #2532)

[jdebacker]

The above was included in the release notes for 3.1.0. Closing.