Workflow updates

Author: bernardd

.github/workflows/on-push.yml

@@ -4,11 +4,12 @@ env:
   MIX_ENV: test
 jobs:
   build:
-    runs-on: ubuntu-latest
+    runs-on: ubuntu-20.04
     strategy:
       matrix:
         otp: ['23.3.4.11']
         elixir: ['1.10.4', '1.13.2']
+        version-type: strict
     steps:
       - uses: actions/checkout@v2
       - uses: erlef/setup-elixir@v1