api.js

import axios from 'axios';

export function getData(_url){

    const _now = Date.now();
    return axios.get(`${_url}?v=${_now}`)
        .catch(error => {
            console.log(error);
        });
};

banner.js

import React from 'react';
import ReactDOM from 'react-dom';
import './Banner.scss';

const Banner = () => {
    return (

        <header className={"contest-banner"}>
            <img src="/assets/top-header-our-daily-winners.png"/>
        </header>
    );

};

export default Banner;

ContestWinnerList.js

import React, { Component } from 'react';
import ReactDOM from 'react-dom';
import './ContestWinnerList.scss';

export default class ContestWinnerList extends Component {
    state = {
        currentTop: 0;
    }

    timeout = null;

    componentDidMount() {
        this.timeout = setInterval(() => { 
            this.setState(prevState => ({ currentTop: prevState + .1}),() => {
               if(this.state.currentTop >= 100) {
                   clearInterval(this.timeout);
                   this.timeout = null;
               }
            }); 
        }, 100);
    }

    componentWillUnmount() {
        if(this.timeout) clearInterval(this.timeout);
    }



    render() {
        console.log(this.props.data);

        if (!this.props.data) {
            // Render loading state ...
            console.log(`NO DATA => ${this.props.data}`);

            return <img className={'loader'} src={'https://www.funnfood.com/images/loader.gif'} />;
        }

        // Otherwise....
        console.log(`DATA FOUND, next line...`);

        return (
            <div className="container">
                <div className="cta-message" style={{ transform: `translateY(-${this.state.currentTop}%)`}}>
                    <ul>
                        {this.props.data.Winners.map((item, index) => (
                            <li key={index}> {/* I don't really recommend using index here, but i don't actually know your data.  Use something unique to each item */}
                                <section class="img-sec">
                                    <img src={item.imgSrc} />
                                </section>
                                <section class="info-sec">
                                    <section class="info-top">{item.prizeDescription}</section>
                                    <section class="info-bottom">{item.winnerName}</section>
                                </section>
                            </li>
                        ))}
                    </ul>
                </div>

                <div className="cta" />
            </div>
        );
    }
}

DailyContestWinners.js (root)

import React, { Component } from 'react';
import ReactDOM from 'react-dom';
import Banner from './stateless/Banner/Banner';
import ContestWinnerList from './stateless/ContestWinnerList/ContestWinnerList';
import {getData} from '../interstitials/leanplum/daily-contest-winners/api';

export default class DailyContestWinners extends Component {


    constructor(props) {

        super(props);

        this.state = {
            externalData: null,
            loading: false,
        };

        this.mounted = false;
    }

    componentDidMount() {
        console.log("DailyContestWinners Component Mounted...");

        this.setState({ loading: true });

        this.mounted = true;

        // Make API request, passing this as a param to setState with exteranlData loaded...

        getData('winners.json').then(response => {
            console.log(response.data);
            console.log(this.mounted);
            if(this.mounted) this.setState({externalData: response.data, loading: false});
            console.log(this.state.externalData);
        });
    }

    componentWillUnmount() {
        this.mounted = false;
    }

    render() {

        if(this.state.externalData !== null){
            console.log("Updated state with payload. Ready to pass and render.");
            return(
                <div className={"view-wrapper"}>
                    <Banner/>
                    {console.log(this.state.externalData.length)}
                    { !this.state.loading && this.state.externalData && <ContestWinnerList data={this.state.externalData}/> }
                </div>
            );
        }

    }
}

if (document.getElementById('daily-contest-view-wrapper')) {

    ReactDOM.render(<DailyContestWinners/>, document.getElementById('daily-contest-view-wrapper'));

}