Simplify the requirements to minimum runtime dependencies (#2313)

Summary: Pull Request resolved: https://github.com/pytorch/audio/pull/2313

Reviewed By: carolineechen, nateanl

Differential Revision: D37799552

Pulled By: mthrok

fbshipit-source-id: 12e27fccb7098f3142e9ca0b748c71325cd324ee

docs/requirements-tutorials.txt

@@ -3,7 +3,6 @@ deep-phonemizer
 boto3
 pandas
 librosa
-numpy<=1.20
 sentencepiece
 nbsphinx
 pandoc

requirements.txt

-torch>=1.4.0
+# Minimum runtime dependencies
+torch
 
-# Required for Windows because it's the only available backend
-SoundFile; sys_platform == 'win32'
-
-# Optional for torchaudio.kaldi_io
-numpy
+# Optional runtime dependencies
 kaldi_io
+SoundFile
 
-# Required for tests only:
-
-# Style-checking for PEP8
-flake8
-
-# Used for comparison of outputs in tests
-librosa>=0.4.3
-scipy
-
-# Unit tests with pytest
-pytest
+# For build and test-time dependencies please refer to CONTRIBUTING.md