Automatic deduction of classifiers and keywords

[sbacchio]

More setup options can be automatically deduced.

Classifiers:

• Development Status based on version, e.g. Pre-alpha (<0.5.0), Alpha (<1.0.0), Stable (<5.0.0), Mature (otherwise)
• License: as done by github
• Programming Language: check how deduced by github
• Python version: 2to3

Keywords:

• they could be deduced from the description, e.g. excluding prepositions