title: NodeJS - Error secret required
body: <p>i am new to working with nodejs and i'm just trying to start a server that is already working with my teammates.
  I am on a mac and already installed all the needed modules with "npm install".
  Now there seems to be a problem with the module "cookie-signature", which is already included in the "express"-module. I am trying to start the program and i get no error, but when i try to open the page on localhost:3000, i get the following error:</p>
  
  <pre><code>/Users/kevinglaap/Sites/Uni/git/node_server/node_modules/express/node_modules/cookie-signature/index.js:19
    if ('string' != typeof secret) throw new TypeError('secret required');
                                         ^
  TypeError: secret required
      at Object.exports.sign (/Users/kevinglaap/Sites/Uni/git/node_server/node_modules/express/node_modules/cookie-signature/index.js:19:40)
      at ServerResponse.end (/Users/kevinglaap/Sites/Uni/git/node_server/node_modules/express/node_modules/connect/lib/middleware/session.js:267:34)
      at ServerResponse.EventEmitter.emit (events.js:93:17)
      at ServerResponse.res.writeHead (/Users/kevinglaap/Sites/Uni/git/node_server/node_modules/express/node_modules/connect/lib/patch.js:73:36)
      at ServerResponse._implicitHeader (http.js:932:8)
      at ServerResponse.OutgoingMessage.end (http.js:767:10)
      at res.end (/Users/kevinglaap/Sites/Uni/git/node_server/node_modules/express/node_modules/connect/lib/middleware/session.js:282:13)
      at /Users/kevinglaap/Sites/Uni/git/node_server/node_modules/express/node_modules/connect/lib/middleware/session/memory.js:73:11
      at process.startup.processNextTick.process._tickCallback (node.js:244:9)
  </code></pre>
  
  <p>The module is never used in the server resources. I already checked for the usage of the "sign"-function, because the error is a fetched error, which signals that the resources may be doing something wrong, but it is only used by express or other modules within express.
  I have been searching the web for days now and haven't found a solution yet. What am i missing? Thanks in advance for your help.</p>