fix no closing iframe tag

was preventing the display of the static version converted with
nbconvert

docs/examples/notebooks/00_notebook_tour.ipynb

@@ -991,19 +991,19 b''
      "cell_type": "code",
      "collapsed": false,
      "input": [
-      "HTML('<iframe src=http://en.mobile.wikipedia.org/?useformat=mobile width=700 height=350>')"
+      "HTML('<iframe src=http://en.mobile.wikipedia.org/?useformat=mobile width=700 height=350></iframe>')"
      ],
      "language": "python",
      "metadata": {},
      "outputs": [
       {
        "html": [
-        "<iframe src=http://en.mobile.wikipedia.org/?useformat=mobile width=700 height=350>"
+        "<iframe src=http://en.mobile.wikipedia.org/?useformat=mobile width=700 height=350></iframe>"
        ],
        "output_type": "pyout",
        "prompt_number": 9,
        "text": [
-        "<IPython.core.display.HTML at 0x10fba2450>"
+        "<IPython.core.display.HTML at 0x1094900d0>"
        ]
       }
      ],
@@ -1238,4 +1238,4 b''
    "metadata": {}
   }
  ]
-}
+}

  No newline at end of file