Backport PR #2117: use explicit url in notebook example

related to  #2115

Either we support gifs, or we don't embed them in notebook example.

Should be backported on 0.13.1

docs/examples/notebooks/00_notebook_tour.ipynb

@@ -431,14 +431,16 b''
      "cell_type": "code",
      "collapsed": false,
      "input": [
-      "Image('http://python.org/images/python-logo.gif')"
+      "Image(url='http://python.org/images/python-logo.gif')"
      ],
      "language": "python",
      "metadata": {},
      "outputs": [
       {
+       "html": [
+        "<img src=\"http://python.org/images/python-logo.gif\" />"
+       ],
        "output_type": "pyout",
-       "png": "R0lGODlh0wBHAPcAAP/////78vf3///35fb19fPy8u/v7//tyPHs2uvq6urq6vXoxv/tYObm5vHl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\njJP63/++2L81zrGOd3zjHvv4x0AOspCHTOQiG/nISE6ykpfc44AAADs=\n",
        "prompt_number": 2,
        "text": [
         "<IPython.core.display.Image at 0x1060e7410>"
@@ -1190,4 +1192,4 b''
    "metadata": {}
   }
  ]
-}
  No newline at end of file
+}