Trying to fix build (python 3.6.8)

environment.yml

@@ -7,7 +7,7 @@ dependencies:
   - psutil==5.7.2
   - pytorch==1.6.0
   - pip==20.2.3
-  - python==3.7
+  - python==3.6.8
   - pip:
       - tensorboard==2.3.0
       - tensorboardx==2.1