Expand description
Assert a command stderr string is not equal to another.
Pseudocode:
(a_command ⇒ stderr) = (b_command ⇒ stderr)
§Example
use assertables::*;
use std::process::Command;
let mut a = Command::new("bin/printf-stderr");
a.args(["%s", "alfa"]);
let mut b = Command::new("bin/printf-stderr");
b.args(["%s", "zz"]);
assert_command_stderr_ne!(a, b);