title: Expected ')' - SVG Transforms throwing error
body: <p>I am using D3 to add attributes to a <code>g</code> element. I am also using D3-selection-multi to make writing the attributes easier (allows you to pass an object to <code>.attrs()</code> function). </p>
  
  <p>using <code>webpack</code> and <code>babel-preset-env</code></p>
  
  <pre><code>d3.select('g').attrs({
    'class': 'thing',
    'transform-origin': '50% 50%',
    'transform': `translate(${opts.w/2} ${opts.h/2}) rotate(${opts.angle}deg)`
  })
  </code></pre>
  
  <p>I keep getting this error: <code>attribute transform: Expected ')'</code></p>