[WIP] Initial code structure of automl

[shane-huang]

• Created package layouts
• Define the main Entrance for time series prediction automl.regression.time_sequence.TimeSequencePredictor
• Define classes for each component
  • automl.feature.abstract.BaseFeatures - feature transformers
    • automl.feature.time_sequence.TimeSequenceFeatures
  • automl.model.abstract.BaseModel - models (including single model and multi model selections).
    • automl.model.VanillaLSTM
    • automl.model.Seq2Seq
    • automl.model.time_sequence.TimeSequenceModel - select models from a bunch of models
  • automl.search.abstract.SearchEngine - search engine interface
    • automl.search.RayTuneSearchEngine
  • automl.pipeline.abstract.Pipeline - only evaluate and predict, no fit, used for deployment
    • automl.pipeline.time_sequence.TimeSequencePipeline
• run through with TimeSequencePredictor, using DummyTimeSequenceFeatures and VanillaLSTM.