Merge pull request adafruit#1269 from brentru/fix-ci-python-3.8

Fix CI for nrf52832/cpb

Author: ladyada

.github/workflows/githubci.yml

@@ -12,9 +12,9 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-    - uses: actions/setup-python@v1
+    - uses: actions/setup-python@v2
       with:
-        python-version: '3.x'
+        python-version: '3.8'
     - uses: actions/checkout@v2
     - uses: actions/checkout@v2
       with: