allow invalid / self-signed certs with http proxies

[joeroback]

for testing https proxies, CI often times generates a self signed cert. this doesn't work with https_proxy and all_proxy environment variables, like say when using a proxy with the aws s3 client.

would it be possible to expose an api to similar to the accept_invalid_certs() or dangerous() or allow users to specify own rustls::client::danger::ServerCertVerifier implementation?

it is very common for a CI or local dev testing to want to test a proxy like, https://localhost:8443

thanks