add simple demo

demo/text-classification/run_classifier.sh

-export CUDA_VISIBLE_DEVICES=0
+export CUDA_VISIBLE_DEVICES=3
 
 # User can select chnsenticorp, nlpcc_dbqa, lcqmc for different task
 DATASET="chnsenticorp"

demo/text-classification/simple_demo.py

@@ -7,7 +7,8 @@ reader = hub.reader.ClassifyReader(hub.dataset.ChnSentiCorp(),
                                    module.get_vocab_path())
 task = hub.create_text_cls_task(feature=outputs["pooled_output"], num_classes=2)
 strategy = hub.AdamWeightDecayStrategy(learning_rate=5e-5)
-config = hub.RunConfig(use_cuda=True, num_epoch=3, strategy=strategy)
+config = hub.RunConfig(
+    use_cuda=True, num_epoch=3, batch_size=32, strategy=strategy)
 feed_list = [
     inputs["input_ids"].name, inputs["position_ids"].name,
     inputs["segment_ids"].name, inputs["input_mask"].name,