Enable network proxy

Maverics will use the network proxy of the environment it is running in when the necessary environment variables are set.

Setup

Maverics supports the HTTPS_PROXY, HTTP_PROXY, NO_PROXY environment variables (and their lowercase counterparts) for configuring network proxies. The environment values may be either a complete URL or a “host[:port]”, in which case the “http” scheme is assumed. The schemes “http”, “https”, and “socks5” are supported. An error is returned if the value is a different form.