Forecast (#162)

* added 'forecast' task with estimators ['fbprophet', 'arima', 'sarimax']

* update setup.py

* add TimeSeriesSplit to 'regression' and 'classification' task

* add 'time' split_type for 'classification' and 'regression' task

Signed-off-by: Kevin Chen <chenkevin.8787@gmail.com>

* feature importance

* variable name

* Update test/test_split.py

Co-authored-by: Chi Wang <wang.chi@microsoft.com>

* Update test/test_forecast.py

Co-authored-by: Chi Wang <wang.chi@microsoft.com>

* prophet installation fail in windows

* upload flaml_forecast.ipynb

Signed-off-by: Kevin Chen <chenkevin.8787@gmail.com>

.github/workflows/python-package.yml

@@ -41,7 +41,7 @@ jobs:
       - name: If linux or mac, install ray
         if: (matrix.os == 'macOS-latest' || matrix.os == 'ubuntu-latest') && matrix.python-version != '3.9'
         run: |
-          pip install -e .[ray]
+          pip install -e .[ray,forecast]
           pip install 'tensorboardX<=2.2'
       - name: Lint with flake8
         run: |