Add single node tensorflow benchmark. (#8513)

Add single node tensorflow benchmark

Author: gongweibao

benchmark/cluster/vgg16/README.md

@@ -20,7 +20,7 @@ Setting environment variable: `MKL_NUM_THREADS=1`.
 | -- | -- | -- | -- | -- |
 | PaddlePaddle Fluid | 15.44 | 16.32 | 16.74 | 16.79 |
 | PaddlePaddle v2 | 15.97 | 17.04 | 17.60 | 17.83 |
-| TensorFlow | - | - | - | - |
+| TensorFlow | 9.09 | 9.10 | 9.24 | 8.66 |
 
 ### Different Batch Size