と出たら+ Rails関連で何かコマンドを打つと以下の様に出るようになった。 SECURITY WARNING: No secret option provided to Rack::Session::Cookie. This poses a security threat. It is strongly recommended that you provide a secret to prevent exploits that may be possible from crafted cookies. This will not be supported in future versions of Rack, and future versions will even invalidate your existing user cookies. 調べてみたら以下のissueで議論されてい