Add shutil for the copying classes over into the model dir

Author: Priya Samuel

roadsigns.ipynb

@@ -484,6 +484,8 @@
    },
    "outputs": [],
    "source": [
+    "import shutil\n",
+    "\n",
     "shutil.copyfile(\"classes.json\", \"model/classes.json\")\n",
     "\n",
     "ds.model(tf, \"roadsigns\", \"model/1\", classes=\"model/classes.json\")"