NO_PUBKEY 575159689BEFB442

Ubuntu 14.04 更新的時候出現了

"Error GPG: http://download.fpcomplete.com stable Release: NO_PUBKEY 575159689BEFB442"

解決方式：

wget -q -O- https://s3.amazonaws.com/download.fpcomplete.com/ubuntu/fpco.key | sudo apt-key add -