title: Multi label tool-tip in Chart.js
body: <p>Recently I moved an old project depending on Chart.js from v1 to v2.</p>
  
  <p>But I am unable to recreate the multi-label tooltip like shown below.
  <a href="https://i.stack.imgur.com/L1ZTy.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/L1ZTy.png" alt="chart.js"></a></p>
  
  <p>In v1 this feature was enabled by default.
  Does anyone know what option I would have to change in order to archive this.</p>
  
  <p>My code so far.</p>
  
  <pre><code>new Chart(document.getElementById('mainChart'), {
          type: 'line',
          data: {
            labels: labels,
            datasets: [
              { data: data, label: "Expenses", fill: false
            ]
          },
          options: {
            animation: { duration: 0 },
            hover: { animationDuration: 0 },
            responsiveAnimationDuration: 0
          }
        });
  </code></pre>