tests: pin EL7 for middleman-el7 scenario to workaorund a Docker bug

duck-rh · duck-rh · commit dcd4cd0c6f78 · 2020-07-10T00:38:52.000+09:00
diff --git a/molecule/middleman-el7/molecule.yml b/molecule/middleman-el7/molecule.yml
@@ -14,7 +14,7 @@ platforms:
     source:
       alias: 'centos/7/amd64'
     # Docker
-    image: 'centos:7'
+    image: 'centos:7.6.1810'
 provisioner:
   inventory:
     group_vars:
