prompt.js

function Prompt(props) {
  return (
    <h1>{this.props.route.header}</h1>
    <div className="col-sm-12">
      <form onSubmit={this.onSubmitUser}>
        <div className="form-group">
          <input 
            className="form-control" 
            placeholder="Github Username"
            type="text"
            onChange={this.onUpdateUser} 
            value={this.state.username} />
        </div>
        <div className="form-group col-sm-4 col-sm-offset-4">
          <button
            className="btn btn-block btn-success"
            type="submit">
              Continue
          </button>
        </div>
      </form>
    </div>
  );
}