func UpdateUser() saves not hashed password to DB

[iliaik]

In user.go function UpdateUser saves not hashed password to DB. So, it should look something like this:

func UpdateUser(w http.ResponseWriter, r *http.Request) {
	user := &models.User{}
	params := mux.Vars(r)
	var id = params["id"]
	db.First(&user, id)
	json.NewDecoder(r.Body).Decode(user)

	pass, err := bcrypt.GenerateFromPassword([]byte(user.Password), bcrypt.DefaultCost)
	if err != nil {
		fmt.Println(err)
		err := ErrorResponse{
			Err: "Password Encryption  failed",
		}
		json.NewEncoder(w).Encode(err)
	}
	user.Password = string(pass)

	db.Save(&user)
	json.NewEncoder(w).Encode(&user)
}

Sorry for posting like this) Sometime I will have a time to post some PR.