1. Enable `security` in the swagger.yaml.
2. Include `basic` auth in `security` to make the generated python
client by `swagger-codegen-cli` work with basic authorization.
3. Include `anonymous` auth in `security` to make APIs of v2.0 generated
by `goswagger` work with `security` middleware.

Closes #11771
Signed-off-by: He Weiwei <hweiwei@vmware.com>