Unable to build from source

[christophetd]

I've been trying to build linkerd-tcp from source (since the docker image doesn't include the latest version, see #82), but I had to make the some changes in order to make it work.

• Changing the rustls commit ID (as instructed in Binary building fails due to incorrect commit-id for rustls in cargo.lock #79)
• Changing the rust image from jimmycuadra/rust:1.16.0 to rust:1.22.1 in the dockerize script, otherwise I get Rust compilations errors.

Would you like a PR to fix that?

[dadjeibaah]

Hi @christophetd thanks for getting linkerd-tcp working, We love PRs and would be happy to get one that fixes the issues you have been running into!