Make unit-test run on 20.04 ubuntu
diff --git a/.github/workflows/unit-tests.yml b/.github/workflows/unit-tests.yml
index 0039e5b..a714b75 100644
--- a/.github/workflows/unit-tests.yml
+++ b/.github/workflows/unit-tests.yml
@@ -3,7 +3,7 @@
 
 jobs:
   run:
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-20.04
     steps:
     - name: Checkout Parent Repository
       uses: actions/checkout@v2