[Request] Update drawSvg Library to latest version

[jondricek]

We have a dependency on drawSvg both in the requirements-dev.txt and setup.py files. It is used in the mitreattack/navlayers section of the library, specifically in the svg_templates.py and svg_objects.py files.

The documentation for drawSvg is here: https://github.com/cduck/drawsvg

It would be great to update our dependency to use the latest version of drawSvg, but the last time we did that, we had the following error: #106

Test

After upgrading the dependency, a good way to test that it worked may be as follows:

• Download the G0016 Navigator Layer file
• Download the Enterprise ATT&CK v13.1 STIX file
• Run the following command in a python virtual environment with the updated version of the mitreattack-python library
  • layerExporter_cli G0016-enterprise-layer.json -m svg -s local --resource enterprise-attack.json -o my-G0016-svg-output.svg
• Check out the my-G0016-svg-output.svg file to see if it looks right!