No option for specifying HTTPS Proxy

[Jimmycon210]

Hi there! In order for us to utilize this package we need to be able to set a proxy to the client.

It does seem this was supported at one point and it may no longer be, as well.

Would be great to see an option for a proxy agent to be added to Asana.ApiClient.instance or something along those lines so we can set it for all of the different clients that are found within the package. Similar to how you can set a token for the package as a whole.

Thank you!