Update smoothing notebook

Author: dshemetov

_delphi_utils_python/delphi_utils/smoothing_docs/COVIDcast Smoothing.ipynb

@@ -14,16 +14,23 @@
    "metadata": {},
    "outputs": [],
    "source": [
+    "import os\n",
+    "from datetime import date\n",
     "import numpy as np\n",
     "import pandas as pd\n",
-    "import os\n",
     "import matplotlib.pyplot as plt\n",
-    "import covidcast\n",
-    "from datetime import date\n",
     "\n",
+    "import covidcast\n",
     "from delphi_utils import Smoother"
    ]
   },
+  {
+   "cell_type": "code",
+   "execution_count": 13,
+   "metadata": {},
+   "outputs": [],
+   "source": []
+  },
   {
    "cell_type": "markdown",
    "metadata": {},