only executes push once, why push two identical data to the array. 
 I am puzzled. 
(this.state.updateTripInfoObj.people.data).push(obj); // 
this.state.travellerInfo.after.temporary.people.data.push(obj);
commit("setTripInfoObj", {
    type: "people",
    res: this.state.updateTripInfoObj.people.data,
});
commit("setTravellerInfo", this.state.travellerInfo);
setTripInfoObj can only do assignment
setTripInfoObj(state, payload) {
    if (payload.type === "people") {
        state.updateTripInfoObj.people.data = payload.res;
    } else {
        const { address, people, stroke, take } = payload;
        state.updateTripInfoObj = {
            people: people || [],
            stroke: stroke || {},
            address: address || [],
            take: take || {},
        };
    }
},
						