title: How to update the chart dynamically with vue-chartjs?
body: <p>I'm using <code>vue.js</code> and <code>vue-chartjs</code> for the first time. 
  In the simplified code example I want to add a label to the chart by pressing the <code>add Label</code> button, but the chart is not updating. My code is based on <a href="https://pusher.com/tutorials/data-visualization-vue-chart" rel="nofollow noreferrer">this</a> tutorial.</p>
  
  <p>I tried calling the <code>render</code> method from the child component, but that does not work.</p>
  
  <p><a href="https://codesandbox.io/s/3rjjv40jym?fontsize=14&amp;module=%2Fsrc%2Fcomponents%2FVisualisation.vue" rel="nofollow noreferrer"><img src="https://codesandbox.io/static/img/play-codesandbox.svg" alt="Edit Vue Chart.js add label"></a></p>
  
  <p>I expected that when I click the <code>add Label</code> button that the label <code>13</code> will be added to the chart.</p>