how to set a https proxy for wsk

Hello there,

I am wondering if can set a http/https proxy for openwhisk-cli.

I search document of repo:openwhisk and found there is some [related instruction](https://github.com/apache/openwhisk/blob/master/docs/cli.md#using-the-openwhisk-cli) for setting it.

I set the mentioned env variable `HTTPS_PROXY` in one of my terminal by `export HTTPS_PROXY=127.0.0.1:8080`, where the `127.0.0.1:8080` is the address of my web proxy.

Then when I invoke an action `wsk action invoke -r {action_name}`, the action flow does not through my proxy.

The web proxy work fine when I invoke the action by `curl --proxy 127.0.0.1:8080 http://localhost:3233/api/v1/web/{action_name}`

Could anyone please tell me how to set up a HTTP/HTTPS proxy for wsk?