avoid showing colors outside of ttys

Author: pietroalbini

Cargo.lock

@@ -32,3 +32,4 @@ percent-encoding = "2.1.0"
 threadpool = "1.8.1"
 tracing = "0.1.16"
 tracing-subscriber = "0.2.8"
+atty = "0.2.14"

Cargo.toml

@@ -38,6 +38,8 @@ impl std::str::FromStr for CliCiPlatform {
 
 pub fn run<F: FnOnce() -> rla::Result<()>>(f: F) {
     tracing_subscriber::fmt()
+        .with_writer(std::io::stderr)
+        .with_ansi(atty::is(atty::Stream::Stderr))
         .with_env_filter(tracing_subscriber::EnvFilter::from_env("RLA_LOG"))
         .init();