!14706 add requirements for unet

From: @zhao_ting_v
Reviewed-by: @c_34,@wuxuejian,@oacjiewen
Signed-off-by: @c_34,@wuxuejian

model_zoo/official/cv/unet/README.md

@@ -144,6 +144,7 @@ Then you can run everything just like on ascend.
         ├── mindspore_hub_conf.py           // hub config file
         ├── postprocess.py                  // unet 310 infer postprocess.
         ├── preprocess.py                   // unet 310 infer preprocess dataset
+        ├── requirements.txt                // Requirements of third party package.
 ```
 
 ### [Script Parameters](#contents)

model_zoo/official/cv/unet/README_CN.md

@@ -148,6 +148,7 @@ bash scripts/docker_start.sh unet:20.1.0 [DATA_DIR] [MODEL_DIR]
         ├── mindspore_hub_conf.py           // hub 配置脚本
         ├── postprocess.py                  // 310 推理后处理脚本
         ├── preprocess.py                   // 310 推理前处理脚本
+        ├── requirements.txt                // 需要的三方库.
 ```
 
 ### 脚本参数

model_zoo/official/cv/unet/requirements.txt

@@ -0,0 +1,2 @@
+opencv-python >= 4.1.2.30
+pillow >= 6.2.0

model_zoo/official/nlp/tinybert/export.py

@@ -48,7 +48,7 @@ task_params = {"SST-2": {"num_labels": 2, "seq_length": 64},
                "QNLI": {"num_labels": 2, "seq_length": 128},
                "MNLI": {"num_labels": 3, "seq_length": 128},
                "TNEWS": {"num_labels": 15, "seq_length": 128},
-               "CLUENER": {"num_labels": 10, "seq_length": 128}}
+               "CLUENER": {"num_labels": 43, "seq_length": 128}}
 
 class Task:
     """