function setupSignalsTrap() {
  _process.on('SIGINT', exit);
  _process.on('SIGTERM', exit);
  _process.on('message', onMessage);

  if (isWindowsTTY(_process)) {
    trapWindowsSignals(_process);
  }
}
Sets up listeners for interruption signals

When one of these signals is caught than raise process.exit()
which enforces `capture-exit` to run registered interruption handlers

@method setupSignalsTrap