Use trove classifiers from official list

Hey,

i put your package up on the Python Package Index (https://pypi.python.org/pypi/python-json-logger).

While doing that, I had to align your classifiers in setup.py with https://pypi.python.org/pypi?%3Aaction=list_classifiers — those changes are attached.

I'd like to promote you as an admin to your package on PyPI, please tell me your PyPI user name.