Fix server.js

in my enviroment, the below error occurred.

```
$ npm start

> component-boilerplate-express@1.0.0 start /Users/kazupon/xxx/yyy/boilerplate-express
> node server/serve


module.js:340
    throw err;
          ^
Error: Cannot find module '.'
    at Function.Module._resolveFilename (module.js:338:15)
    at Function.Module._load (module.js:280:25)
    at Module.require (module.js:364:17)
    at require (module.js:380:17)
    at Object.<anonymous> (/Users/kazupon/xxx/yyy/boilerplate-express/server/serve.js:5:18)
    at Module._compile (module.js:456:26)
    at Object.Module._extensions..js (module.js:474:10)
    at Module.load (module.js:356:32)
    at Function.Module._load (module.js:312:12)
    at Function.Module.runMain (module.js:497:10)

npm ERR! component-boilerplate-express@1.0.0 start: `node server/serve`
npm ERR! Exit status 8
npm ERR!
npm ERR! Failed at the component-boilerplate-express@1.0.0 start script.
npm ERR! This is most likely a problem with the component-boilerplate-express package,
npm ERR! not with npm itself.
npm ERR! Tell the author that this fails on your system:
npm ERR!     node server/serve
npm ERR! You can get their info via:
npm ERR!     npm owner ls component-boilerplate-express
npm ERR! There is likely additional logging output above.
npm ERR! System Darwin 13.1.0
npm ERR! command "/Users/kazupon/bin/.nvm/v0.10.28/bin/node" "/Users/kazupon/bin/.nvm/v0.10.28/bin/npm" "start"
npm ERR! cwd /Users/kazupon/xxx/yyy/boilerplate-express
npm ERR! node -v v0.10.28
npm ERR! npm -v 1.4.9
npm ERR! code ELIFECYCLE
npm ERR!
npm ERR! Additional logging details can be found in:
npm ERR!     /Users/kazupon/xxx/yyy/boilerplate-express/npm-debug.log
npm ERR! not ok code 0
```

I fixed this issues.