Fix scenario path in config detector

When running pytest with custom scenario name,
make config detection taking into account the scenario specific
molucule config file.

For example, some scenarios could use podman, while other ones -
a delegated driver.

Change-Id: Ied74290876d28f6fb2011aa3d9ccd77c0c90bea1
Signed-off-by: Bogdan Dobrelya <bdobreli@redhat.com>

.config/molecule/config_podman.yml

@@ -1,5 +1,9 @@
 ---
+driver:
+  name: podman
+
 log: true
+
 platforms:
   - name: centos
     hostname: centos

tests/test_molecule.py

@@ -18,10 +18,10 @@ import pytest
 import yaml
 
 
-def set_proper_molecule_config(role_path):
+def set_proper_molecule_config(role_path, scenario='default'):
     mol_config_file = "config.yml"
-    if os.path.exists(os.path.join(role_path, 'molecule', 'default/molecule.yml')):
-        molecule_path = os.path.join(role_path, 'molecule', 'default/molecule.yml')
+    if os.path.exists(os.path.join(role_path, 'molecule', f'{scenario}/molecule.yml')):
+        molecule_path = os.path.join(role_path, 'molecule', f'{scenario}/molecule.yml')
         with open(molecule_path) as content:
             data = yaml.safe_load(content)
         if 'driver' in data.keys() and data['driver']['name'] == 'podman':
@@ -35,8 +35,11 @@ def set_proper_molecule_config(role_path):
 def test_molecule(pytestconfig):
     cmd = ['python', '-m', 'molecule']
     scenario = pytestconfig.getoption("scenario")
+    if not scenario:
+        scenario = 'default'
     ansible_args = pytestconfig.getoption("ansible_args")
-    cmd.extend(['--base-config', set_proper_molecule_config(os.getcwd())])
+    cmd.extend(['--base-config', set_proper_molecule_config(os.getcwd(),
+                                                            scenario)])
 
     if ansible_args:
         cmd.append('converge')