Bump mimemagic version

Bumped mimemagic version to 0.3.7 due to the previous version being
yanked.

Author: solongordon

ruby/activerecord/Gemfile.lock

@@ -68,7 +68,8 @@ GEM
     marcel (0.3.3)
       mimemagic (~> 0.3.2)
     method_source (1.0.0)
-    mimemagic (0.3.6)
+    mimemagic (0.3.7)
+      nokogiri (~> 1.11.2)
     mini_mime (1.0.2)
     mini_portile2 (2.5.0)
     minitest (5.14.4)