Implement subplot command

[leouieda]

This is a very cool new command.

[GengPeiLin]

Hi Leo,

Is there any progress to use gmt.Figure() with subplot?
Really love to see it works!!

GP

[leouieda]

Sorry, @GengPeiLin. No progress on that front yet. I've been busy with other things and haven't had much time for expanding the features yet.

[weiji14]

Just mentioning that @JFordHydro was interested in this feature during the FOSS4G 2019 Oceania workshop. Will see if we can get a Pull Request in tomorrow during Community Day tomorrow!