Log Message:
py-matplotlib: updated to 2.1.2

2.1.2:
This release fixes a number of critical bugs:
- fix a typo in mlab.cohere which yielded incorrect results
- allow nonposx / nonposy to pass through loglog
- fix color comparisons when finding handles with legend
- fixes a recursive draw bug and a major performance regression in
  Qt5Agg backend
- fix a re-draw bug in WxAgg
- fix image scaling with high-bit depth integers
- revert the busy-cursor