Attempt to unpin torch version for Github Action. (#4384)

.github/workflows/self-push.yml

@@ -35,7 +35,7 @@ jobs:
     - name: Install dependencies
       run: |
         source .env/bin/activate
-        pip install torch==1.4.0
+        pip install torch
         pip install .[sklearn,testing]
 
     - name: Are GPUs recognized by our DL frameworks