Remove the widget cell from the example

examples/lab/example.ipynb

@@ -41,18 +41,6 @@
     "print('some more stdout text', flush=True)"
    ]
   },
-  {
-   "cell_type": "code",
-   "execution_count": 1,
-   "metadata": {
-    "collapsed": true
-   },
-   "outputs": [],
-   "source": [
-    "from ipywidgets import IntSlider\n",
-    "IntSlider() # slider appears at the top of the notebook"
-   ]
-  },
   {
    "cell_type": "markdown",
    "metadata": {},
@@ -133,7 +121,7 @@
    "name": "python",
    "nbconvert_exporter": "python",
    "pygments_lexer": "ipython3",
-   "version": "3.5.1"
+   "version": "3.4.4"
   }
  },
  "nbformat": 4,