Fix mktemp to be MacOS compatible
Fix mktemp to be MacOS compatible

letsencrypt/boulder,mehmooda/boulder,sophie-h/boulder,jcjones/boulder,KyleChamberlin/boulder,bmw/boulder,r0ro/boulder,lucasallan/boulder,benileo/boulder,hlandauf/boulder,r0ro/boulder,ZCloud-Firstserver/boulder,mozmark/boulder,mehmooda/boulder,mozmark/boulder,ibukanov/boulder,mehmooda/boulder,jcjones/boulder,mozmark/boulder,postfix/boulder,jsha/boulder,patf/boulder,sophie-h/boulder,bmw/boulder,hlandauf/boulder,benileo/boulder,jfrazelle/boulder,benileo/boulder,jsha/boulder,sophie-h/boulder,bmw/boulder,KyleChamberlin/boulder,postfix/boulder,ZCloud-Firstserver/boulder,jfrazelle/boulder,letsencrypt/boulder,letsencrypt/boulder,mehmooda/boulder,patf/boulder,hlandauf/boulder,patf/boulder,mozmark/boulder,r0ro/boulder,KyleChamberlin/boulder,jcjones/boulder,jfrazelle/boulder,ZCloud-Firstserver/boulder,postfix/boulder,ZCloud-Firstserver/boulder,jsha/boulder,postfix/boulder,lucasallan/boulder,jcjones/boulder,KyleChamberlin/boulder,patf/boulder,ibukanov/boulder,ibukanov/boulder,jfrazelle/boulder,lucasallan/boulder,hlandauf/boulder,r0ro/boulder,benileo/boulder