add metaspore flow init/create scene command

[javyxu]

1. add metaspore flow init scene command Use metaspore flow init --scene_name scene_01 --scheduler_mode SagaMaker command can generate an initialized yaml as follows, you can change the configuration, such as scheduling mode, data source, intermediate result store, recommendation policy:

   name: scene_01
   scheduler_mode:
     name: SageMaker
     config:
       roleArn: ''
       securityGroups: []
       subnets: []
       s3Endpoint: ''
       s3WorkDir: ''
   datasource:
     connect_info:
       type: mysql
       host: 127.0.0.1
       port: 3306
       database: ''
       user: ''
       password: ''
     user_tab_info:
       name: user
       user_id_column_name: user_id
       age_col_name: ''
       gender_col_name: ''
       city_col_name: ''
     item_tab_info:
       name: item
       item_id_column_name: item_id
       price_column_name: ''
       title_column_name: ''
       brand_column_name: ''
       category_column_name: ''
       url_column_name: ''
       image_column_name: ''
       description_column_name: ''
     trans_tab_info:
       name: interaction
       user_id_column_name: user_id
       item_id_column_name: item_id
       timestamp_column_name: timestamp
   middle_result_storage:
     type: Mongo
     host: 127.0.0.1
     port: 27017
     database: ''
     user: ''
     password: ''
     authsource: admin
   recommend_strategy:
   recommend_result_count: 200

2. add metaspore flow create scene command Use metaspore flow create --values ./scene_01.yml command can generate scene yamls, and then go into the scene folder to execute metaspore flow up/down/status command can start scene、stop scene and get scene status.