One-dimensional test functions now return one-dimensional array

[damar-wicaksono]

• Previously, all one-dimensional test functions return two-dimensional arrays with a single column; this behavior is inconsistent with the other test functions.

This PR should resolve Issue #221.

[codecov[bot]]

Codecov Report

Patch coverage: 100.00% and no project coverage change.

Comparison is base (398ba89) 98.30% compared to head (6fda996) 98.31%.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## dev #222 +/- ## ======================================= Coverage 98.30% 98.31% ======================================= Files 44 44 Lines 1597 1598 +1 Branches 132 132 ======================================= + Hits 1570 1571 +1 Misses 15 15 Partials 12 12 ``` | [Impacted Files](https://app.codecov.io/gh/damar-wicaksono/uqtestfuns/pull/222?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Damar+Wicaksono) | Coverage Δ | | |---|---|---| | [src/uqtestfuns/test\_functions/forrester.py](https://app.codecov.io/gh/damar-wicaksono/uqtestfuns/pull/222?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Damar+Wicaksono#diff-c3JjL3VxdGVzdGZ1bnMvdGVzdF9mdW5jdGlvbnMvZm9ycmVzdGVyLnB5) | `100.00% <100.00%> (ø)` | | | [src/uqtestfuns/test\_functions/oakley\_ohagan\_1d.py](https://app.codecov.io/gh/damar-wicaksono/uqtestfuns/pull/222?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Damar+Wicaksono#diff-c3JjL3VxdGVzdGZ1bnMvdGVzdF9mdW5jdGlvbnMvb2FrbGV5X29oYWdhbl8xZC5weQ==) | `100.00% <100.00%> (ø)` | |

:umbrella: View full report in Codecov by Sentry.
:loudspeaker: Do you have feedback about the report comment? Let us know in this issue.