Remove/fix some todo
Remove/fix some todo

FiloSottile/dns,benbearchen/dns,skynet/dns,AlexCheong/dns,skyportsystems/dns,jmhodges/dns,tempbottle/dns,bragr/dns,Git-Host/dns,janstk/dns,letsencrypt/dns,ErikDubbelboer/dns,jdef/dns,asergeyev/dns,flebarbe/dns,bboreham/dns,tsenart/dns,curtiszimmerman/dns,ym/go-dns,tonnerre/golang-dns,modulexcite/dns,Psiphon-Inc/dns,hugozhu/dns,miekg/dns,rolandshoemaker/dns,ezoic/dns,cloudflare/dns,michaelharo/dns,josephyzhou/dns