crypto/tls: more Unix root certificate locations

Hard work done by
http://mercurial.selenic.com/wiki/CACertificates

R=golang-dev, gri
CC=golang-dev
https://golang.org/cl/5276043

root_unix.go

@@ -12,6 +12,8 @@ import (
 // Possible certificate files; stop after finding one.
 var certFiles = []string{
 	"/etc/ssl/certs/ca-certificates.crt", // Linux etc
+	"/etc/pki/tls/certs/ca-bundle.crt",   // Fedora/RHEL
+	"/etc/ssl/ca-bundle.pem",             // OpenSUSE
 }
 
 func initDefaultRoots() {