Issue 330: fix test variable mistake and quant name

[sschmidt23]

@eacharles pointed out something obvious that I missed: that the test was actually feeding in ez values rather than specz values, which somehow did not cause a crash until now. That and changing the name from quant_piecewise to quant in one of the PIT functions now has all of the tests running for me on my local branch.

[sschmidt23]

A couple of tests failed because of the changes going on in the minimal tables_io imports PR. A new tagged version of qp with tables_io[full] should fix this shortly, at which point the tests should pass once we re-launch them.

[codecov[bot]]

Codecov Report

Patch coverage: 100.00% and no project coverage change.

Comparison is base (13309f1) 100.00% compared to head (42cb705) 100.00%.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #331 +/- ## ========================================= Coverage 100.00% 100.00% ========================================= Files 38 38 Lines 2507 2505 -2 ========================================= - Hits 2507 2505 -2 ``` | Flag | Coverage Δ | | |---|---|---| | unittests | `100.00% <100.00%> (ø)` | | Flags with carried forward coverage won't be shown. [Click here](https://docs.codecov.io/docs/carryforward-flags?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=LSSTDESC#carryforward-flags-in-the-pull-request-comment) to find out more. | [Impacted Files](https://codecov.io/gh/LSSTDESC/RAIL/pull/331?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=LSSTDESC) | Coverage Δ | | |---|---|---| | [src/rail/evaluation/evaluator.py](https://codecov.io/gh/LSSTDESC/RAIL/pull/331?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=LSSTDESC#diff-c3JjL3JhaWwvZXZhbHVhdGlvbi9ldmFsdWF0b3IucHk=) | `100.00% <ø> (ø)` | | | [src/rail/evaluation/metrics/pit.py](https://codecov.io/gh/LSSTDESC/RAIL/pull/331?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=LSSTDESC#diff-c3JjL3JhaWwvZXZhbHVhdGlvbi9tZXRyaWNzL3BpdC5weQ==) | `100.00% <100.00%> (ø)` | | Help us with your feedback. Take ten seconds to tell us [how you rate us](https://about.codecov.io/nps?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=LSSTDESC). Have a feature suggestion? [Share it here.](https://app.codecov.io/gh/feedback/?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=LSSTDESC)

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