create MANIFEST.in to include necessary files for sdist

Author: yoyolicoris

MANIFEST.in

@@ -0,0 +1,8 @@
+recursive-include torchlpc *.py
+recursive-include torchlpc *.h
+recursive-include torchlpc *.cpp
+recursive-include torchlpc *.c
+recursive-include torchlpc *.cu
+recursive-include tests *.py
+recursive-exclude * __pycache__
+recursive-exclude * *.pyc