__slots__ is meaningless.

It is meaningless to use ```__slots__``` in ```__init__```. Python creates ```__dict__``` and ```__weakref__```  before ```__init__``` invocation.
Merge pull request #9 from go1dshtein/patch-1

__slots__ moved from body of __init__ to class definition.
Training naive bayes with ambiguous entries - to be verified with more data
Merge branch 'master' of https://github.com/martinthenext/eth_ml
Classifier trained on ambiguous. to be verified with more data
Aesthetical fix
issue 7