Add sampled model 'czce_hfts'
Add sampling batch tasks
Update query helper
Fix: schema column name error, 'clost' to 'close'
Update data aggregated function
Ignore no use data
Merge branch 'feature/add_aggregate_function_rake' into develop
Migration: change column name 'ticktime' to 'time' and 'frequency' to 'frequence'
Fill empty/gap for 'second, minute, hour'
Merge branch 'feature/padding_empty_value_to_aggregated_data' into develop
Merge branch 'release/v0.0.2'