Adjust for latest PyTorch version. (#112)

Author: acburigo

tutorials/PytorchOnnxExport.ipynb

@@ -98,14 +98,13 @@
    "metadata": {},
    "outputs": [],
    "source": [
-    "from torch.autograd import Variable\n",
     "import torch.onnx\n",
     "import torchvision\n",
     "\n",
     "# Standard ImageNet input - 3 channels, 224x224,\n",
     "# values don't matter as we care about network structure.\n",
     "# But they can also be real inputs.\n",
-    "dummy_input = Variable(torch.randn(1, 3, 224, 224))\n",
+    "dummy_input = torch.randn(1, 3, 224, 224)\n",
     "# Obtain your model, it can be also constructed in your script explicitly\n",
     "model = torchvision.models.alexnet(pretrained=True)\n",
     "# Invoke export\n",