Install pytorch on github CI.

.github/workflows/rust.yml

@@ -8,6 +8,15 @@ jobs:
     name: Build and test
     runs-on: ubuntu-latest
     steps:
+      - name: Install pytorch
+        run: |
+          pip3 install torch==2.0.0 torchvision==0.15.0 --index-url https://download.pytorch.org/whl/cpu
+          echo LIBTORCH_USE_PYTORCH=1 >> "$GITHUB_ENV"
+          echo "$LD_LIBRARY_PATH"
+          echo LD_LIBRARY_PATH="$(python -m site --user-site)/torch/lib:$LD_LIBRARY_PATH" >> "$GITHUB_ENV"
+          echo "LALALA="
+          cat "$GITHUB_ENV"
+
       - name: Checkout code
         uses: actions/checkout@master
 
@@ -22,18 +31,24 @@ jobs:
 
       - name: Build
         uses: actions-rs/cargo@v1
+        env:
+          LIBTORCH_USE_PYTORCH: 1
         with:
           command: build
           args: --release --features full --color=always
 
       - name: Clippy
         uses: actions-rs/clippy-check@v1
+        env:
+          LIBTORCH_USE_PYTORCH: 1
         with:
           token: ${{ secrets.GITHUB_TOKEN }}
           args: --release --features full
 
       - name: Test
         uses: actions-rs/cargo@v1
+        env:
+          LIBTORCH_USE_PYTORCH: 1
         with:
           command: test
           args: --release --features full --color=always