vamcc

Support proxy option instead of HTTP_PROXY env variable

3

**Is your feature request related to a problem? Please describe.** Using `HTTP_PROXY` env variable will affect other requests which may also come from some other third-party packages. And not every...

**Is your feature request related to a problem? Please describe.** I want to add a proxy for request from `googleapis`. But `env.HTTP_PROXY` will affect requests from other request client(not only...