tests/net/quay: insecure test times out

[steveej]

This blocks CI and thus all PRs will fail until resolved, e.g. https://travis-ci.org/camallo/dkregistry-rs/jobs/628065374.

[lucab]

For reference:

test net::quay_io::test_quayio_insecure ... test net::quay_io::test_quayio_insecure has been running for over 60 seconds

thread 'net::quay_io::test_quayio_insecure' panicked at 'called `Result::unwrap()` on an `Err` value: Error(Reqwest(Error(Hyper(Error(Connect, Os { code: 110, kind: TimedOut, message: "Connection timed out" })), "http://quay.io/v2/")), State { next_error: None, backtrace: InternalBacktrace })', src/libcore/result.rs:1165:5

[lucab]

It looks like quay.io:80 changed behavior and now it simply ignores TCP connections. I think we can safely ignore the test for now.