added syscerts dep

vendor/github.com/jackspirou/syscerts/root_plan9.go

@@ -0,0 +1,32 @@
+// Copyright 2012 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build plan9
+
+package syscerts
+
+import (
+	"crypto/x509"
+	"io/ioutil"
+)
+
+// Possible certificate files; stop after finding one.
+var certFiles = []string{
+	"/sys/lib/tls/ca.pem",
+}
+
+func initSystemRoots() {
+	roots := x509.NewCertPool()
+	for _, file := range certFiles {
+		data, err := ioutil.ReadFile(file)
+		if err == nil {
+			roots.AppendCertsFromPEM(data)
+			systemRoots = roots
+			return
+		}
+	}
+
+	// All of the files failed to load. systemRoots will be nil which will
+	// trigger a specific error at verification time.
+}