docs: update README.md [skip ci]

Author: allcontributors[bot]

README.md

@@ -71,7 +71,7 @@ Thanks goes to these wonderful people ([emoji key](https://allcontributors.org/d
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       <td align="center"><a href="https://medium.com/@pbadeer"><img src="https://avatars.githubusercontent.com/u/467756?v=4?s=100" width="100px;" alt="Preston Badeer"/><br /><sub><b>Preston Badeer</b></sub></a><br /><a href="https://github.com/adamghill/django-unicorn/commits?author=pbadeer" title="Documentation">📖</a></td>
-      <td align="center"><a href="https://github.com/stat1c-void"><img src="https://avatars.githubusercontent.com/u/9142081?v=4?s=100" width="100px;" alt="Sergei"/><br /><sub><b>Sergei</b></sub></a><br /><a href="https://github.com/adamghill/django-unicorn/commits?author=stat1c-void" title="Documentation">📖</a></td>
+      <td align="center"><a href="https://github.com/stat1c-void"><img src="https://avatars.githubusercontent.com/u/9142081?v=4?s=100" width="100px;" alt="Sergei"/><br /><sub><b>Sergei</b></sub></a><br /><a href="https://github.com/adamghill/django-unicorn/commits?author=stat1c-void" title="Documentation">📖</a> <a href="https://github.com/adamghill/django-unicorn/commits?author=stat1c-void" title="Code">💻</a> <a href="https://github.com/adamghill/django-unicorn/commits?author=stat1c-void" title="Tests">⚠️</a></td>
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