Increase timeout to 30min

Author: Maik Hummel

.github/workflows/docker.yml

@@ -13,7 +13,7 @@ env:
 jobs:
   main:
     runs-on: ubuntu-20.04
-    timeout-minutes: 20
+    timeout-minutes: 30
     steps:
       - name: Check out the repo
         uses: actions/checkout@v2