FR: Provide override flag for terminal check

Nobody has claimed this yet.

My cook stage in failing inside a [Kaniko](https://github.com/GoogleContainerTools/kaniko) automated builder running inside a docker container, it seems to have fooled `atty::is(atty::Stream::Stdout)`

It would be helpful to have a flag to force it to continue.

Output:

```
INFO[0102] Taking snapshot of full filesystem...
INFO[0108] cmd: /bin/sh
INFO[0108] args: [-c cargo chef cook --recipe-path recipe.json]
INFO[0108] Running: [/bin/sh -c cargo chef cook --recipe-path recipe.json]
WARNING stdout appears to be a terminal.
cargo-chef is not meant to be run in an interactive environment and will overwrite some existing files (namely any `lib.rs`, `main.rs` and `Cargo.toml` it finds).

To continue anyway, type `yes`: error building image: error building stage: failed to execute command: waiting for process to exit: exit status 1
exit status 1
```

If you have a preferred name for the flag, I can make a PR.

No file or test is named. Start by locating the terminal check that emits the stdout warning and the command-line argument handling around it; reproduce the Kaniko-in-Docker failure described above. Done means an override flag lets this non-interactive build continue when the terminal check is triggered.

Written by the indexing model from the issue text.