support multi-module (#4)

* add multimodule
* re-package modules

model/rest/command.go

@@ -0,0 +1,16 @@
+package rest
+
+import "encoding/json"
+
+type Command struct {
+	Actor    string            `json:"actor" binding:"notblank"`
+	Commands []json.RawMessage `json:"cmd"   binding:"min=1"`
+}
+
+func (o Command) MarshalBinary() (data []byte, err error) {
+	return json.Marshal(&o)
+}
+
+func (o *Command) UnmarshalBinary(data []byte) error {
+	return json.Unmarshal(data, o)
+}