Fix Molecule CI workflow since docker plugin has moved.

Author: geerlingguy

.github/workflows/ci.yml

@@ -64,7 +64,7 @@ jobs:
           python-version: '3.x'
 
       - name: Install test dependencies.
-        run: pip3 install ansible molecule[docker] docker
+        run: pip3 install ansible molecule molecule-plugins[docker] docker
 
       - name: Run Molecule tests.
         run: molecule test