title: using objectFit in gatsby-image props
body: <p>I'm trying to use this property on gatsby-image: <code>objectFit="none"</code>
  its having no effect - the default of <code>"cover"</code> appears instead. </p>
  
  <p>I can fix this with css, but hoping there's no need to do this, any ideas. </p>
  
  <p>Here's the code for the image:</p>
  
  <pre><code>    &lt;Img
          fluid={product.variants[imageLoc].image.localFile.childImageSharp.fluid}
          objectFit="none"
      /&gt;
  </code></pre>