Reformat API Calls

[bloycey]

API Calls shouldn't include the setStates within the function and should instead use the then on the promise. E.g. Like this:

componentDidMount() {
    this.callApi()
      .then(res => this.setState({ response: res.express }))
      .catch(err => console.log(err));
  }

  callApi = async () => {
    const response = await fetch("/api/hello");
    const body = await response.json();
    if (response.status !== 200) throw Error(body.message);
    return body;
  };

I also need to set up error handling on all my routes.