Fix expanded income to include non-taxable pension income

[martinholmer]

#1888 has raised a number of issues that we hope to resolve in the near future.

One of the questions #1888 raises in my mind is: What exactly is included in expanded_income?

It turns out that answering that question is difficult because of the convoluted logic currently used in Tax-Calculator to compute expanded_income. We hope to simply that logic in a forthcoming pull request.

But one thing is clear: non-taxable pension and annuity income, e01500 - e01700, is not currently included in expanded_income even though it makes up slightly more than one-third of total pension and annuity income, e01500, in the 2011 PUF. The amount of income omitted from expanded_income is roughly $330 billion in 2011.

This pull request corrects the logic of the expanded_income calculation to include non-taxable pension and annuity income. It also revises some puf.csv test results to reflect the fix of the puf.csv file implemented in taxdata pull request 158. And it revises some non-PUF test results to reflect changes caused by the correction of the definition of expanded_income.

[codecov-io]

Codecov Report

Merging #1897 into master will not change coverage.
The diff coverage is n/a.

@@          Coverage Diff           @@
##           master   #1897   +/-   ##
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  Coverage     100%    100%           
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  Files          37      37           
  Lines        3308    3308           
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  Hits         3308    3308

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