Improvements to setup.py options

I'm opening this PR, in relation to #67, to discuss the following:

* Name: Should it be ``Shiva``, ``shiva``, ``shiva-server``, ``Shiva-Server``, etc...? What's the naming convention?
* Classifiers: Are they ok? Is anything missing?
* Should we add ``license``, ``long_description`` and/or ``platform``?
* Any other option that should be included.

Once we define this I'll register the software at PyPi :smile_cat: