Fix PHPUnit tests not running in CI and failing test

[meszarosrob]

Please check if the PR fulfills these requirements

• [ ] The commit message follows our guidelines
• [ ] Tests for the changes have been added (for bug fixes/features)
• [ ] Docs have been added/updated (for bug fixes/features)

What kind of change does this PR introduce? (Bug fix, feature, docs update, ...)

It fixes a failing test and the CI where PHPUnit tests are not actually run.

What is the current behavior? (You can also link to an open issue here)

There's a failing test, but that is never caught because the PHPUnit tests are not run.

What is the new behavior (if this is a feature change)?

PHPUnit runs again in the CI, and the failing test passes.

Does this PR introduce a breaking change? (What changes might users need to make in their application due to this PR?)

No.

Other information:

None.

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Comparison is base (cc91569) 95.90% compared to head (d5e4f9e) 98.86%. Report is 4 commits behind head on master.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## master #37 +/- ## ============================================ + Coverage 95.90% 98.86% +2.95% - Complexity 170 189 +19 ============================================ Files 9 9 Lines 464 528 +64 ============================================ + Hits 445 522 +77 + Misses 19 6 -13 ``` | [Flag](https://app.codecov.io/gh/inpsyde/modularity/pull/37/flags?src=pr&el=flags&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=inpsyde) | Coverage Δ | | |---|---|---| | [unittests](https://app.codecov.io/gh/inpsyde/modularity/pull/37/flags?src=pr&el=flag&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=inpsyde) | `98.86% <100.00%> (+2.95%)` | :arrow_up: | 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=inpsyde#carryforward-flags-in-the-pull-request-comment) to find out more. | [Files](https://app.codecov.io/gh/inpsyde/modularity/pull/37?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=inpsyde) | Coverage Δ | | |---|---|---| | [src/Container/ContainerConfigurator.php](https://app.codecov.io/gh/inpsyde/modularity/pull/37?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=inpsyde#diff-c3JjL0NvbnRhaW5lci9Db250YWluZXJDb25maWd1cmF0b3IucGhw) | `100.00% <100.00%> (ø)` | | | [src/Container/PackageProxyContainer.php](https://app.codecov.io/gh/inpsyde/modularity/pull/37?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=inpsyde#diff-c3JjL0NvbnRhaW5lci9QYWNrYWdlUHJveHlDb250YWluZXIucGhw) | `100.00% <100.00%> (+30.76%)` | :arrow_up: | | [src/Package.php](https://app.codecov.io/gh/inpsyde/modularity/pull/37?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=inpsyde#diff-c3JjL1BhY2thZ2UucGhw) | `100.00% <100.00%> (+1.94%)` | :arrow_up: | ... and [1 file with indirect coverage changes](https://app.codecov.io/gh/inpsyde/modularity/pull/37/indirect-changes?src=pr&el=tree-more&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=inpsyde)

:umbrella: View full report in Codecov by Sentry.
:loudspeaker: Have feedback on the report? Share it here.

[Chrico]

Thanks for your work ☕ Good catch! 💪🏻