message: fix(dropdown): add aria attributes
  fixes
diff: @@ -45,13 +45,17 @@ export class DocsDropdown {
  const button = (
  <button
  class="Dropdown-button"
  + aria-haspopup="menu"
  + aria-expanded={this.isOpen ? 'true' : 'false'}
  onClick={this.toggle.bind(this)}>
  {this.label} <DownArrow/>
  </button>
  );
  const panel = (
  - <div class="Dropdown-panel">
  + <div
  + role="menu"
  + class="Dropdown-panel">
  <slot/>
  </div>
  );
  