Use new NumPy building practice
Use new NumPy building practice

Switches the recipe over to building against `numpy 1.11` and allowing
the run time version to be `numpy 1.11` or greater. Should help
consolidate CI builds a bit.

nanshe-org/rank_filter,DudLab/rank_filter,jakirkham/rank_filter,nanshe-org/rank_filter,jakirkham/rank_filter,jakirkham/rank_filter,nanshe-org/rank_filter,DudLab/rank_filter,DudLab/rank_filter