adds poetry, pytest

[datajango]

• Adds poetry for development
• Adds pytest
• Adds a DEV,md for developer instructions

[datajango]

Will hold off until we talk. There are significant problems with re-wx that I just became aware of.

[jamesdbrock]

I for one would like to hear about what problems you’re thinking of.

[bkZHD]

Me too!

[datajango]

Hi Guys. Before I jump in to this noble effort with you I thought we should discuss the future of re-wx, Let's start with a complex control #24 and see where it leads us.