Update components to use fat arrow functions

[bfbachmann]

Currently we define our class functions like this

class MyClass extends Component {
    constructor(props) {
        ...

        this.myFunction = this.myFunction.bind(this);
    }

    myFunction(args) {
        ...
    }
}

We should instead define our functions like this

class MyClass extends Component {
    constructor(props) {
        ...
    }

    myFunction: (args) => {
        ...
    }
}