Bump mimemagic from 0.3.3 to 0.3.4

Bumps [mimemagic](https://github.com/minad/mimemagic) from 0.3.3 to 0.3.4.
- [Release notes](https://github.com/minad/mimemagic/releases)
- [Changelog](https://github.com/minad/mimemagic/blob/master/CHANGELOG.md)
- [Commits](mimemagicrb/mimemagic@v0.3.3...v0.3.4)

Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

Author: dependabot-preview[bot]

Gemfile.lock

@@ -197,7 +197,7 @@ GEM
     mime-types (3.3.1)
       mime-types-data (~> 3.2015)
     mime-types-data (3.2019.1009)
-    mimemagic (0.3.3)
+    mimemagic (0.3.4)
     mini_mime (1.0.2)
     mini_portile2 (2.4.0)
     minitest (5.14.0)