NumPy will drop Python 2 support

The NumPy project is phasingout support for Python 2. "The Python core team plans to stopsupporting Python 2 in 2020. The NumPy project has supported both Python 2and Python 3 in parallel since 2010, and has found that supporting Python 2is an increasing burden on our limited resources; thus, we plan toeventually drop Python 2 support as well. Now that we're entering the finalyears of community-supported Python 2, the NumPy project wants to clarifyour plans, with the goal of to helping our downstream ecosystem make plansand accomplish the transition with as little disruption aspossible." NumPy releases will fully support both Python 2 andPython 3 until December 31, 2018. New feature releases will support onlyPython 3 as of January 1, 2019. (Thanks to Nathaniel Smith)