title: How do I catch that enter is pressed in Polymer 1.0 paper-input
body: <p>How do I catch when <kbd>enter</kbd> is pressed in Polymer 1.0 <code>paper-input</code>?</p>
  
  <p>I tried with the <code>on-bind-value-changed</code> that is exposed through the <code>iron-input</code>, but it seems it only differentiates with letters in the event argument where <code>e.detail</code> is <code>null</code> on all other keys, such as <kbd>enter</kbd>, <kbd>tab</kbd>, etc.</p>