Switch to Super Linter slim image (#35)

* Switch to Super Linter slim image

* Switch to test version of spamassassin-action

* Update ci.yml

Author: hspaans

Diff for: .github/workflows/ci.yml

@@ -19,7 +19,7 @@ jobs:
         uses: actions/checkout@v2
 
       - name: Lint Code Base
-        uses: github/super-linter@v4
+        uses: github/super-linter/slim@v4
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
 
@@ -32,4 +32,4 @@ jobs:
         uses: actions/checkout@v2
 
       - name: Verify SpamAssassin rules
-        uses: hspaans/spamassassin-action@v1
+        uses: hspaans/spamassassin-action@v2