Small bug fixes

- Logo DOM sctrucutre now valid, no longer <a/> within </a>
 - `data-wd-key` not longer required
 - `maputnik-doc-popup` not longer hidden by LayerEditor accordion

src/components/inputs/SelectInput.jsx

@@ -4,7 +4,7 @@ import PropTypes from 'prop-types'
 class SelectInput extends React.Component {
   static propTypes = {
     value: PropTypes.string.isRequired,
-    "data-wd-key": PropTypes.string.isRequired,
+    "data-wd-key": PropTypes.string,
     options: PropTypes.array.isRequired,
     style: PropTypes.object,
     onChange: PropTypes.func.isRequired,