Timeout for running, building, linting any code

Eg:

fn main() { /*abc*/ }

   Compiling rand_os v0.1.2
   Compiling iovec v0.1.2
   Compiling num_cpus v1.10.0
   Compiling net2 v0.2.33
   Compiling memchr v2.2.0
   Compiling time v0.1.42
   Compiling rand v0.4.6
   Compiling xattr v0.2.2
   Compiling filetime v0.2.4
   Compiling atty v0.2.11
   Compiling termion v1.5.1
   Compiling MacTypes-sys v2.1.0
   Compiling memmap v0.7.0
   Compiling thread-id v3.3.0
   Compiling crossbeam-epoch v0.7.1
   Compiling crossbeam-epoch v0.3.1
   Compiling quote v0.6.11
   Compiling deflate v0.7.19
/root/entrypoint.sh: line 8:     7 Killed                  timeout --signal=KILL ${timeout} "$@"

[shepmaster]

I see #6734 has been merged,

There are multiple steps:

1. The fix has to be merged into the Cargo codebase (that was https://github.com/rust-lang/cargo/pull/6734)
2. The Cargo update needs to be merged into Rust (this is https://github.com/rust-lang/rust/pull/59143)
3. Rust needs to be released (should be the next night, assuming nothing prevents the build from succeeding)

[ehuss]

Yea, I think I have a fix. Testing with docker is a little slow.