go-couchbase does not discard connections that have timeout on read.

If a read operation times out, client.go:Do() and client.go:doBulkGet() incorrectly choose not to discard the connection.
This means that a non operational connection may be chosen for subsequent gets (bulk or not), which may lead to yet more failed gets.

The read timeout is a symptom of something bigger, so creating new connections is not panacea, however once the something bigger is resolved, we shouldn't have timed out connections still lying around.