fix: unwrap panic with more info

[futurist]

fix: #34

The panic info will be printed as below:

thread 'tokio-runtime-worker' panicked at /Users/my/.cargo/registry/src/index.crates.io-6f17d22bba15001f/http-mitm-proxy-0.7.1/src/lib.rs:267:81:
connect uri: https://www2.bing.com:443/ipv6test/test: handshake failure
note: run with RUST_BACKTRACE=1 environment variable to display a backtrace

[hatoo]

Thank you!
I think those panics should be replaced by Result type but I'll happily merge this as a temporal fix.

[futurist]

@hatoo Can you do some change from expect/unwrap to Result? The lib now not stable to use.

[hatoo]

@futurist how do you mean 'not stable'?
panics are handled by tokio runtime and doesn't cause an unexpected exit.

I'll do some work on saturday.