Release v4.0.1
Changes
- Add IsString instance by @newhoggy
- Merge pull request #163 from haskell-works/is-string-instance Add IsString instance by @AlexeyRaga
- Fix stats/socket callback types by @phile314
- Merge pull request #166 from phile314/cb_ints Fix stats/socket callback types by @AlexeyRaga
- Allow rdkafka free stats callback payload by @AlexeyRaga