Update the graph-NSL tutorials to use TF 2.0.1 with GPU support.

This version is stable and avoids relying on nightly TF 2.2.0 builds which are under constant churn and may not be stable.

PiperOrigin-RevId: 301676978

Author: arjung

g3doc/tutorials/graph_keras_lstm_imdb.ipynb

@@ -114,7 +114,7 @@
       "source": [
         "## Requirements\n",
         "\n",
-        "1.  Install TensorFlow 2.2.x to create an interactive development environment with eager execution.\n",
+        "1.  Install TensorFlow 2.0.x to create an interactive development environment with eager execution.\n",
         "2.  Install the Neural Structured Learning package.\n",
         "3.  Install tensorflow-hub."
       ]
@@ -129,7 +129,7 @@
       },
       "outputs": [],
       "source": [
-        "!pip install tf-nightly==2.2.0.dev20200218"
+        "!pip install tensorflow-gpu==2.0.1"
       ]
     },
     {

g3doc/tutorials/graph_keras_mlp_cora.ipynb

@@ -116,7 +116,7 @@
         "id": "hgSLDi0SyBuO"
       },
       "source": [
-        "1.  Install TensorFlow 2.2.x to create an interactive development environment with eager execution.\n",
+        "1.  Install TensorFlow 2.0.x to create an interactive development environment with eager execution.\n",
         "2.  Install the Neural Structured Learning package."
       ]
     },
@@ -130,7 +130,7 @@
       },
       "outputs": [],
       "source": [
-        "!pip install tf-nightly==2.2.0.dev20200218"
+        "!pip install tensorflow-gpu==2.0.1"
       ]
     },
     {