Move to vendor

Signed-off-by: Olivier Gambier <olivier@docker.com>

vendor/github.com/bugsnag/osext/osext_plan9.go

@@ -0,0 +1,16 @@
+// 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.
+
+package osext
+
+import "syscall"
+
+func executable() (string, error) {
+	f, err := Open("/proc/" + itoa(Getpid()) + "/text")
+	if err != nil {
+		return "", err
+	}
+	defer f.Close()
+	return syscall.Fd2path(int(f.Fd()))
+}