Fix test_image_overlay for py27

Author: Martin Journois

examples/ImageOverlay.ipynb

@@ -14,6 +14,25 @@
     "It may happen that you want to draw an image on you map. Here are example on how to do that."
    ]
   },
+  {
+   "cell_type": "code",
+   "execution_count": 1,
+   "metadata": {
+    "collapsed": false
+   },
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "Let's start\n"
+     ]
+    }
+   ],
+   "source": [
+    "print \"Let's start\""
+   ]
+  },
   {
    "cell_type": "code",
    "execution_count": 1,
@@ -22,8 +41,6 @@
    },
    "outputs": [],
    "source": [
-    "import sys\n",
-    "sys.path.insert(0,'..')\n",
     "import folium\n",
     "from folium.six import PY3\n",
     "from folium import plugins"