CI: use matrix build to test differnt container OSs

fixes #51

.github/workflows/ci.yml

@@ -30,8 +30,12 @@ on:
   workflow_dispatch:
 
 jobs:
-  defaults:
+  build-run-test:
     runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        container_os: [centos7, rocky8, rocky9]
+        environment_profile: [development]
     steps:
       - name: Check out repository contents
         uses: actions/checkout@v3
@@ -42,6 +46,9 @@ jobs:
           make test-doc
       - name: Build images
         run: |
+          ln -s Dockerfile.${{ matrix.container_os }} Dockerfile
+          ln -s docker-compose_${{ matrix.environment_profile }}.yml docker-compose.yml
+          ln -s ${{ matrix.environment_profile }}.env .env
           make init
           echo "# NOTE: use absolute paths to current dir to get docker bind mounts to work" > ci.env
           echo "DOCKER_MIGRID_ROOT=$PWD" >> ci.env