Update GitHub workflow for Service Account support

Author: ondrajodas

.github/workflows/push.yml

@@ -10,6 +10,7 @@ env:
   CLIENT_ID: '${{ secrets.CLIENT_ID }}'
   CLIENT_SECRET: '${{ secrets.CLIENT_SECRET }}'
   REFRESH_TOKEN: '${{ secrets.REFRESH_TOKEN }}'
+  SERVICE_ACCOUNT_JSON: '${{ secrets.SERVICE_ACCOUNT_JSON }}'
 jobs:
   tests:
     runs-on: ubuntu-latest
@@ -31,4 +32,5 @@ jobs:
           -e CLIENT_ID \
           -e CLIENT_SECRET \
           -e REFRESH_TOKEN \
-          ${{env.APP_IMAGE}} composer ci
+          -e SERVICE_ACCOUNT_JSON \
+          ${{env.APP_IMAGE}} composer ci