chore: required parameter and remove .venv in .gitignore

Author: feliperezende-barbosa

.gitignore

@@ -6,7 +6,6 @@ __pycache__/
 env/
 env27/
 venv/
-.venv/
 .python-version
 
 # PTVS analysis

src/azure-cli/azure/cli/command_modules/apim/_params.py

@@ -520,7 +520,7 @@ def load_arguments(self, _):
         c.argument('service_name', options_list=['--service-name', '-n'],
                    help='The name of the API Management service instance.')
         c.argument('backend_id', arg_type=backend_id, help='Identifier of the Backend.')
-        c.argument('url', help='Required. Backend service URL.')
+        c.argument('url', required=True, help='Backend service URL.')
         c.argument('protocol', arg_type=get_enum_type(BACKEND_PROTOCOLS),
                    help='Protocol used to communicate with the backend service. Possible values include: `http`, `soap`.')
         c.argument('description', help='Description of the Backend. May include HTML formatting tags.')