old_contents: import React, { Component } from 'react'
  import { Route, Link } from 'react-router-dom'
  import moneyImg from '../images/money.svg'
  
  const introText = [
    "As a council member you have $969.2 Million to fund services for all of Austin, Texas",
    "This money comes from the General Fund for 2016-17",
    "This money helps Austin run programs and employs 13,838 civil servants",
    "Outside effects like population change and overall economic activity cause the fund to vary year to year",
    "It's now up to you to make sure we allocate the funds and create a fair budget."
  ]
  
  const IntroPage = (props) => {
    const nextId = Number(props.params.id) + 1;
    const nextUrl = `/intro/${nextId}`;
    const isLastIntro = introText.length === Number(props.params.id);
  
    return (
      <div className="intro">
        <Link to="/dashboard" className="intro__skip">Skip Intro</Link>
        <img src={moneyImg} className="intro__img" alt="Money Emoji"/>
        <p className="intro__text">{props.text}</p>
        {
          isLastIntro
          ? <Link to="/dashboard" className="intro__start-button"><span>Get Started</span></Link>
          : <Link to={nextUrl} className="intro__next-button">Next</Link>
        }
      </div>
    )
  }
  
  export default class Intro extends Component {
    render () {
      return (
        <Route path='/intro/:id' render={({match}) => <IntroPage {...match} text={introText[match.params.id - 1]} />} />
      )
    }
  }
  
new_contents: import React, { Component } from 'react'
  import { Route, Link } from 'react-router-dom'
  import PropTypes from 'prop-types';
  import moneyImg from '../images/money.svg'
  
  const introText = [
    "As a council member you have $969.2 Million to fund services for all of Austin, Texas",
    "This money comes from the General Fund for 2016-17",
    "This money helps Austin run programs and employs 13,838 civil servants",
    "Outside effects like population change and overall economic activity cause the fund to vary year to year",
    "It's now up to you to make sure we allocate the funds and create a fair budget."
  ]
  
  const IntroPage = (props) => {
    const nextId = Number(props.params.id) + 1;
    const nextUrl = `/intro/${nextId}`;
    const isLastIntro = introText.length === Number(props.params.id);
  
    return (
      <div className="intro">
        <Link to="/dashboard" className="intro__skip">Skip Intro</Link>
        <img src={moneyImg} className="intro__img" alt="Money Emoji"/>
        <p className="intro__text">{props.text}</p>
        {
          isLastIntro
          ? <Link to="/dashboard" className="intro__start-button"><span>Get Started</span></Link>
          : <Link to={nextUrl} className="intro__next-button">Next</Link>
        }
      </div>
    )
  }
  
  export default class Intro extends Component {
    render () {
      return (
        <Route path='/intro/:id' render={({match}) => <IntroPage {...match} text={introText[match.params.id - 1]} />} />
      )
    }
  }
  
  IntroPage.propTypes = {
    params: PropTypes.shape({
      id: PropTypes.string,
    }).isRequired,
    text: PropTypes.string.isRequired,
  };
  
  
subject: Add PropTypes for intro