message: Missing import and pip install of tf-nightly in workshop notebook
diff: {
  "cells": [
  + {
  + "cell_type": "code",
  + "execution_count": 0,
  + "metadata": {
  + "colab": {
  + "autoexec": {
  + "startup": false,
  + "wait_interval": 0
  + }
  + },
  + "colab_type": "code",
  + "id": "yFn4b8J0CKQV"
  + },
  + "outputs": [],
  + "source": [
  + "pip install -U tf-nightly"
  + ]
  + },
  {
  "cell_type": "code",
  "execution_count": 0,
  },
  "outputs": [],
  "source": [
  + "import os\n",
  + "import matplotlib.pyplot as plt\n",
  "import tensorflow as tf\n",
  - "from tensorflow.contrib import autograph\n",
  - "\n",
  - "import matplotlib.pyplot as plt"
  + "from tensorflow.contrib import autograph"
  ]
  },
  {
  