Matplotlib version upgrade

Mantid is still using matplotlib 2.2.3 (4.2 and the latest nightly). Is there a plan to bring it more up to date, for example the 3.1.1 (stable) or 3.1.2 (newest) versions? (This is on Windows, other platforms may vary)

Searching the matplotlib examples I came across which doesn’t work in Mantid. I’d like to use something similar to plot my data with wavelength on one x-axis and the corresponding energy on another (clearly one of the two has non-linear ticks). This is from a script rather than expecting to do it via the plot dialogs!

As of Mantid moving to Python 3 (in the Nightly, hopefully very soon!) we will be moving to at least matplotlib 3.1 on Windows and Mac for sure