Replace make with python alternative (poe)

[wren]

This is the start of work on #1361, but does not completely fix it.

This PR:

• Gets rid of Makefile, and the dependency on make
• Adds Poe the Poet (poe plays nice with both poetry and tox, and is easy to setup)
• Adds tasks previously from Makefile into pyproject.toml (in new format for poe)
• Updates documentation to reference poe instead of make

The reason to do this is to reduce outside dependencies (poe only needs Python), and is more inclusive for Windows devs (since they previously had to install make separately, and usually with some trouble).

Checklist

• I have read the contributing doc.
• I have included a link to the relevant issue number.
• I have checked to ensure there aren't other open pull requests
  for the same issue.
• I have written new tests for these changes, as needed.