support storybook 4 active property

package.json

@@ -1,6 +1,6 @@
 {
   "name": "react-storybook-addon-static-markup",
-  "version": "0.1.0",
+  "version": "0.1.1",
   "description": "",
   "main": "index.js",
   "scripts": {

register.js

@@ -89,13 +89,18 @@ var StaticMarkup = function (_React$Component) {
     key: 'render',
     value: function render() {
       var markup = this.state.markup;
+      // setting it to true to support past
+      // versions of storybook, which might not
+      // have active property.
 
+      var _props$active = this.props.active,
+          active = _props$active === undefined ? true : _props$active;
 
-      return _react2.default.createElement(
+      return active ? _react2.default.createElement(
         'div',
         { style: styles.markupPanel },
         markup
-      );
+      ) : null;
     }
 
     // This is some cleanup tasks when the StaticMarkup panel is unmounting.

src/register.js

@@ -40,12 +40,15 @@ class StaticMarkup extends React.Component {
 
   render() {
     const { markup } = this.state;
-
-    return (
+    // setting it to true to support past
+    // versions of storybook, which might not
+    // have active property.
+    const { active = true } = this.props
+    return active ? (
       <div style={styles.markupPanel}>
         { markup }
       </div>
-    );
+    ) : null;
   }
 
   // This is some cleanup tasks when the StaticMarkup panel is unmounting.