Declare python 3.8 support

https://q-ctrl.atlassian.net/browse/QENG-631

Author: charmasaur

.github/workflows/on-push.yml

@@ -44,7 +44,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        python: [3.6, 3.7]
+        python: [3.6, 3.7, 3.8]
     steps:
     - uses: actions/checkout@v1
     - name: Install Python dependencies
@@ -66,4 +66,4 @@ jobs:
       run: |
         source <(curl -sL http://ci.q-ctrl.com)
         ./ci vault login -r ${{ secrets.VAULT_ROLE_ID }} -s ${{ secrets.VAULT_SECRET_ID }}
-        ./ci docker run qctrl/python-build:3.7 /scripts/publish-dev-version.sh
+        ./ci docker run qctrl/python-build:3.7 /scripts/publish-dev-version.sh