change root path to relative

Tutorial_NN.ipynb

@@ -57,7 +57,7 @@
         "import seaborn as sns\n",
         "\n",
         "device = torch.device('cuda' if torch.cuda.is_available() else 'cpu')\n",
-        "root = '/content/'\n",
+        "root = 'content/'\n",
         "\n",
         "sns.set(color_codes=True)"
       ],