Cleanup most of the remaining nits (#578)

test/tun.go

@@ -0,0 +1,47 @@
+package test
+
+import (
+	"errors"
+	"io"
+	"net"
+
+	"github.com/slackhq/nebula/iputil"
+)
+
+type NoopTun struct{}
+
+func (NoopTun) RouteFor(iputil.VpnIp) iputil.VpnIp {
+	return 0
+}
+
+func (NoopTun) Activate() error {
+	return nil
+}
+
+func (NoopTun) CidrNet() *net.IPNet {
+	return nil
+}
+
+func (NoopTun) DeviceName() string {
+	return "noop"
+}
+
+func (NoopTun) Read([]byte) (int, error) {
+	return 0, nil
+}
+
+func (NoopTun) Write([]byte) (int, error) {
+	return 0, nil
+}
+
+func (NoopTun) WriteRaw([]byte) error {
+	return nil
+}
+
+func (NoopTun) NewMultiQueueReader() (io.ReadWriteCloser, error) {
+	return nil, errors.New("unsupported")
+}
+
+func (NoopTun) Close() error {
+	return nil
+}