modify classifiers, add python_requires, change name in pypi to py-arima to avoid name collision.
modify classifiers, add python_requires, change name in pypi to py-arima to avoid name collision.

tgsmith61591/pyramid,alkaline-ml/pmdarima,alkaline-ml/pmdarima,tgsmith61591/pyramid,alkaline-ml/pmdarima,tgsmith61591/pyramid