Should the build tags of conncheck rather be opt-in instead of op-out?

Current build tag: // +build !windows,!appengine

This might fail to compile on some platforms, or not?

you are right. it fails on plan9.

I wrote very simple compile checker. https://gist.github.com/shogo82148/a7a61b7a1652bff07fc0dfd07ceb2122

The following is an abstract of the result for current master branch b66d043

$ENV{GOOS}="plan9"; $ENV{GOARCH}="amd64";
# github.com/go-sql-driver/mysql
./conncheck.go:42:15: undefined: syscall.EAGAIN
./conncheck.go:42:40: undefined: syscall.EWOULDBLOCK

I wrote very simple compile checker. https://gist.github.com/shogo82148/a7a61b7a1652bff07fc0dfd07ceb2122

We should maybe add a Travis job for that

Hi @julienschmidt! Just came back from my holidays. How can I help with the release process? I see you already wrote the changelog notes. 🙇

#1054 and this PR still need a review and must be merged. Other than that, I think we're ready to tag the release. 🎉