marked dependency is insecure version

As described in https://github.com/jsdoc3/jsdoc/issues/1489 , there is a security vulnerability in the marked package. We should update as soon jsdoc published the fixed version on npmjs.com.

<img width="748" alt="bildschirmfoto 2018-01-10 um 10 40 24" src="https://user-images.githubusercontent.com/1038777/34765783-bc12cea4-f5f2-11e7-8ae7-8837c6d7ff23.png">