Un-pin torch version

Summary:
We released the restriction of torch version due to the version requirement conflicts with ax package.
We also removed some redundant code due to the removal of neural prophet model

Reviewed By: yangbk560

Differential Revision: D34878121

fbshipit-source-id: 1878e81b338164f16c3e180b899507f928632177

kats/models/__init__.py

@@ -19,13 +19,6 @@
 from . import globalmodel  # noqa
 from . import metalearner  # noqa
 from . import model  # noqa
-
-try:
-    from . import neuralprophet  # noqa
-except ImportError:
-    import logging
-
-    logging.warning("kats.models.neuralprophet not available (requires neuralprophet)")
 from . import nowcasting  # noqa
 from . import prophet  # noqa
 from . import quadratic_model  # noqa

test_requirements.txt

@@ -9,5 +9,5 @@ parameterized>=0.8.1
 plotly>=2.2.1
 pymannkendall>=1.4.1
 pytest-mpl>=0.12
-torch<=1.8.1
+torch
 tqdm>=4.36.1