add reboot command

pi/roverd/command.go

@@ -31,6 +31,7 @@ type inboundMessage struct {
 	Horn         *hornPayload         `json:"horn,omitempty"`
 	NightVision  *nightVisionPayload  `json:"nightVision,omitempty"`
 	Song         *songPayload         `json:"song,omitempty"`
+	Reboot       *rebootPayload       `json:"reboot,omitempty"`
 }
 
 type driveDirectPayload struct {
@@ -87,6 +88,10 @@ type songNote struct {
 	Duration int `json:"duration"`
 }
 
+type rebootPayload struct {
+	DelayMs int `json:"delayMs,omitempty"`
+}
+
 type ackMessage struct {
 	Type   string `json:"type"`
 	ID     string `json:"id"`