rustls support

[clux]

for #66 - trying to learn the crypto stuff to do this properly.

if anyone's reading this and see any obvious mistakes, please call out :-)

[clux]

Ok. I'm definitely doing client certs wrong. Not sure how to convert the client cert + client key data (from kube config) into a reqwest::Identity atm. But we are pretty close - despite having commented out a few non-standard features.

[clux]

or, maybe I am. but something is definitely not working. getting 403s across the board.

been debugging with:

NAMESPACE=dev cargo run --example pod_informer --no-default-features --features=openapi,native-tls
NAMESPACE=dev cargo run --example pod_informer --no-default-features --features=openapi,rustls-tls

with

diff --git examples/pod_informer.rs examples/pod_informer.rs
index d5aef09e..9719cfd3 100644
--- examples/pod_informer.rs
+++ examples/pod_informer.rs
@@ -12,7 +12,7 @@ type Pod = Object<PodSpec, PodStatus>;
 
 #[tokio::main]
 async fn main() -> anyhow::Result<()> {
-    env::set_var("RUST_LOG", "info,kube=trace");
+    env::set_var("RUST_LOG", "debug,reqwest=trace,kube=trace");
     env_logger::init();
     let config = config::load_kube_config().await?;
     let client = APIClient::new(config);

and seeing how far it gets.. so far 403 on first GET response in the Informer.

[clux]

Did a merge with master, then noticed this...
55c8feb

..This branch actually works after the one-line change in Cargo.toml

[clux]

basic support is there - works with my clusters, but probably some dragons in here.
also, have commented out the oauth2 module, because i would rather have the initial support in here. will raise a separate issue for it while I merge this.