[*] fix old archives.format_overrides.format option, closes #301

Author: pashagolub

.goreleaser.yml

@@ -23,7 +23,7 @@ archives:
   wrap_in_directory: true
   format_overrides:
     - goos: windows
-      format: zip
+      formats: ['zip']
   files:
     - LICENSE
     - README.md