Add test and compatible_data fields for new policy parameters

[martinholmer]

This pull request adds a test to check that every policy parameter in the current_law_policy.json file has a compatible_data field, and it also adds a compatible_data field to each new parameter added in pull requests #1818 and #1819.

Because of the complexity of test_compatible_data, which was merged in pull request #1614, and the change in what is current-law policy, which happened in pull request #1803, there are still 7 (out of 45 pre_release tests) test failures in this pull request. The 11 parameters that failed test_compatible_data are as follows:

taxcalc$ py.test -n4 -m compatible_data 2>&1 | grep ERROR: | grep -v errmsg | sort
ERROR: _ID_BenefitSurtax_Switch not False for cps
ERROR: _ID_Casualty_c not False for puf
ERROR: _ID_Casualty_frt not False for puf
ERROR: _ID_Miscellaneous_c not False for cps
ERROR: _ID_Miscellaneous_c not False for puf
ERROR: _ID_Miscellaneous_frt not False for cps
ERROR: _ID_Miscellaneous_frt not False for puf
ERROR: _ID_crt not False for cps
ERROR: _ID_crt not False for puf
ERROR: _ID_ps not False for cps
ERROR: _ID_ps not False for puf

As you can see, all eleven failing parameters have to do with itemized deductions, the rules for which have changed substantially with the passage of TCJA.

[codecov-io]

Codecov Report

Merging #1822 into master will not change coverage.
The diff coverage is n/a.

@@          Coverage Diff           @@
##           master   #1822   +/-   ##
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  Coverage     100%    100%           
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  Files          37      37           
  Lines        3098    3098           
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  Hits         3098    3098

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