title: How to set axes' step size in Chart.js 2?
body: <p>I created a simple line chart using chart.js with 3 Y axes:
  <a href="https://codepen.io/anon/pen/dZVgKw" rel="noreferrer">https://codepen.io/anon/pen/dZVgKw</a></p>
  
  <p>As you can see, the last one is going from 10 to 20 without any number between. How can I set step size here?</p>
  
  <p>This is how I add an axe:</p>
  
  <pre><code>{
    id: 'C',
    type: 'linear',
    position: 'left',
    ticks: {
      max: 10,
      min: 20,
    },
  }
  </code></pre>
  
  <p>Thanks.</p>