feat: Added a cli test

tests/test_cli.py

+import sys
+import subprocess
+
+
+def run_command(cmd: str, args: str):
+    cmd = f"{sys.executable} -m bitia {cmd} {args}"
+    print(f"Executing `{cmd}`")
+    return subprocess.check_output(cmd)
+
+
+def test_cli_sanity():
+    output = run_command("run", '"ls -ltr /"')
+    print(output.decode().rstrip())
+    assert len(output) > 20, "Too little output"
+
+
+if __name__ == "__main__":
+    test_cli_sanity()