add extra requirements in tutorial

Author: zylo117

tutorial/train_shape.ipynb

@@ -46,7 +46,7 @@
    "execution_count": null,
    "outputs": [],
    "source": [
-    "!pip install pycocotools numpy==1.16.0 opencv-python tqdm tensorboard tensorboardX pyyaml matplotlib\n",
+    "!pip install pycocotools numpy==1.16.0 opencv-python tqdm tensorboard tensorboardX pyyaml webcolors matplotlib\n",
     "!pip install torch==1.4.0\n",
     "!pip install torchvision==0.5.0"
    ],
@@ -293,4 +293,4 @@
  },
  "nbformat": 4,
  "nbformat_minor": 0
-}
+}