[MNT] Support Python 3.9

Author: xuyxu

.github/workflows/build-and-test.yml

@@ -12,7 +12,7 @@ jobs:
     strategy:
       matrix:
         os: [ubuntu-latest, windows-latest]
-        python-version: [3.6, 3.7, 3.8]
+        python-version: [3.6, 3.7, 3.8, 3.9]
     steps:
     - uses: actions/checkout@v2
     - name: Set up Python

requirements.txt

@@ -1,3 +1,3 @@
-torch>=0.4.1
+torch>=1.4.0
 torchvision>=0.2.2
 scikit-learn>=0.23.0