wercker integration (Closes #9)

Fixes #9.

Someone with the sufficient rights has to create a wercker account and add this app for this to work.
Currently wercker runs `gulp fulltest` and `gulp docs`.
The generated docs will be pushed to the branch gh-pages.
Example of generated docs can be seen here: https://leipert.github.io/Jassa-Core/

If something else is needed let me know, for example email or IRC notification.

The wercker profile of my fork can be found here: https://app.wercker.com/#applications/53f14060836da8ab08000737