add python 3.8 testing (#915)

* add python 3.8 test

* update info

* py38 >> torch 1.2

* skip py38 minimal

* changelog

Co-authored-by: William Falcon <waf2107@columbia.edu>

.github/workflows/ci-testing.yml

@@ -20,8 +20,12 @@ jobs:
       # max-parallel: 6
       matrix:
         os: [ubuntu-18.04, windows-2016, macOS-10.15]
-        python-version: [3.6, 3.7]
+        python-version: [3.6, 3.7, 3.8]
         requires: ['minimal', 'latest']
+        exclude:
+          # excludes node 4 on macOS
+          - python-version: 3.8
+            requires: 'minimal'
 
     # Timeout: https://stackoverflow.com/a/59076067/4521646
     timeout-minutes: 20