fix yaml version issue with config yaml dump (#75344)

now tests can run in other pythons (really yaml pkg versions)
  also cleaned up diff_failure for unimplemented flow

lib/ansible/cli/config.py

@@ -274,7 +274,7 @@ class ConfigCLI(CLI):
                 if subkey == 'env':
                     data.append('%s%s=%s' % (prefix, entry, default))
                 elif subkey == 'vars':
-                    data.append(prefix + to_text(yaml.dump({entry: default}, Dumper=AnsibleDumper), errors='surrogate_or_strict'))
+                    data.append(prefix + to_text(yaml.dump({entry: default}, Dumper=AnsibleDumper, default_flow_style=False), errors='surrogate_or_strict'))
                 data.append('')
 
         return data

test/integration/targets/config/aliases

@@ -1,4 +1 @@
 shippable/posix/group1
-skip/python2
-skip/python3.6
-skip/python3.7

test/integration/targets/config/runme.sh

@@ -31,15 +31,9 @@ cleanup() {
 
 trap 'cleanup' EXIT
 
-diff_failure() {
-    if [[ $INIT = 0 ]]; then
-        echo "FAILURE...diff mismatch!"
-        exit 1
-    fi
-}
 # check a-c init per format
 for format in "vars" "ini" "env"
 do
 	ANSIBLE_LOOKUP_PLUGINS=./ ansible-config init types -t lookup -f "${format}" > "files/types.new.${format}"
-	diff -u "files/types.${format}" "files/types.new.${format}"|| diff_failure
+	diff -u "files/types.${format}" "files/types.new.${format}"
 done