dep: phpunit 추가

vendor/sebastian/recursion-context/README.md

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+# sebastian/recursion-context
+
+[![CI Status](https://github.com/sebastianbergmann/recursion-context/workflows/CI/badge.svg)](https://github.com/sebastianbergmann/recursion-context/actions)
+[![Type Coverage](https://shepherd.dev/github/sebastianbergmann/recursion-context/coverage.svg)](https://shepherd.dev/github/sebastianbergmann/recursion-context)
+
+## Installation
+
+You can add this library as a local, per-project dependency to your project using [Composer](https://getcomposer.org/):
+
+```
+composer require sebastian/recursion-context
+```
+
+If you only need this library during development, for instance to run your project's test suite, then you should add it as a development-time dependency:
+
+```
+composer require --dev sebastian/recursion-context
+```