message: Fix a non-critical problem in TFLite README
  Currently it uses `bazel build` to build non-optimized binary,
  then `bazel run` to build and run optimized binary. It doubles
  the required build time to try Toco converter.
diff: @@ -154,7 +154,7 @@ Here is a sample command line to convert the frozen Graphdef to '.lite' format f
  ```
  bazel build tensorflow/contrib/lite/toco:toco
  -bazel run --config=opt tensorflow/contrib/lite/toco:toco -- \
  +bazel-bin/tensorflow/contrib/lite/toco/toco -- \
  --input_file=(pwd)/mobilenet_v1_1.0_224/frozen_graph.pb \
  --input_format=TENSORFLOW_GRAPHDEF --output_format=TFLITE \
  --output_file=/tmp/mobilenet_v1_1.0_224.lite --inference_type=FLOAT \
  