Add logging about Terrapin exception (#108)

Author: guillaumebriday-pa

lib/paperclip/media_type_spoof_detector.rb

@@ -76,6 +76,8 @@ def type_from_file_command
       Paperclip.run("file", "-b --mime :file", file: @file.path).
         split(/[:;\s]+/).first
     rescue Terrapin::CommandLineError
+      Paperclip.log("Problem getting type from `file` command. Possible that `file` doesn't exist on this system. Content Type validations don't work without this.")
+
       ""
     end