Update contributors [skip ci]

Author: hipstersmoothie

.all-contributorsrc

@@ -388,7 +388,8 @@
       "avatar_url": "https://avatars.githubusercontent.com/u/349833?v=4",
       "profile": "http://danielholmes.org/",
       "contributions": [
-        "code"
+        "code",
+        "test"
       ]
     },
     {

README.md

@@ -180,7 +180,7 @@ Thanks goes to these wonderful people ([emoji key](https://allcontributors.org/d
     <td align="center"><a href="https://github.com/CruScanlan"><img src="https://avatars.githubusercontent.com/u/24949142?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Cru Scanlan</b></sub></a><br /><a href="https://github.com/jimp-dev/jimp/commits?author=CruScanlan" title="Code">💻</a></td>
     <td align="center"><a href="https://autery.net/"><img src="https://avatars.githubusercontent.com/u/2135631?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Curtis Autery</b></sub></a><br /><a href="https://github.com/jimp-dev/jimp/commits?author=ceautery" title="Code">💻</a></td>
     <td align="center"><a href="https://github.com/dan335"><img src="https://avatars.githubusercontent.com/u/499401?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Dan</b></sub></a><br /><a href="https://github.com/jimp-dev/jimp/commits?author=dan335" title="Code">💻</a></td>
-    <td align="center"><a href="http://danielholmes.org/"><img src="https://avatars.githubusercontent.com/u/349833?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Daniel Holmes</b></sub></a><br /><a href="https://github.com/jimp-dev/jimp/commits?author=danielholmes" title="Code">💻</a></td>
+    <td align="center"><a href="http://danielholmes.org/"><img src="https://avatars.githubusercontent.com/u/349833?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Daniel Holmes</b></sub></a><br /><a href="https://github.com/jimp-dev/jimp/commits?author=danielholmes" title="Code">💻</a> <a href="https://github.com/jimp-dev/jimp/commits?author=danielholmes" title="Tests">⚠️</a></td>
   </tr>
   <tr>
     <td align="center"><a href="https://danieltschinder.com/"><img src="https://avatars.githubusercontent.com/u/231804?v=4?s=100" width="100px;" alt=""/><br /><sub><b>Daniel Tschinder</b></sub></a><br /><a href="https://github.com/jimp-dev/jimp/commits?author=danez" title="Code">💻</a></td>