[added] Make modal portal have the dialog role (#223)

closes #212

Author: claydiffrient

Diff for: lib/components/ModalPortal.js

@@ -201,7 +201,8 @@ var ModalPortal = module.exports = React.createClass({
           tabIndex: "-1",
           onKeyDown: this.handleKeyDown,
           onMouseDown: this.handleContentMouseDown,
-          onMouseUp: this.handleContentMouseUp
+          onMouseUp: this.handleContentMouseUp,
+          role: "dialog"
         },
           this.props.children
         )

Diff for: specs/Modal.spec.js

@@ -58,6 +58,13 @@ describe('Modal', function () {
     unmountModal();
   });
 
+  it('renders the modal content with a dialog aria role ', function () {
+    var child = 'I am a child of Modal, and he has sent me here...';
+    var component = renderModal({isOpen: true}, child);
+    equal(component.portal.refs.content.getAttribute('role'), 'dialog');
+    unmountModal();
+  });
+
   it('has default props', function() {
     var node = document.createElement('div');
     Modal.setAppElement(document.createElement('div'));