Add init command

[Kyle-Verhoog]

This will create a default riotfile.py in the current directory if one does not already exist.

riot init

[brettlangdon]

Would be fun too if it initialized a Venv with all versions of Python found on the system.

e.g.

from riot import Venv

venv = Venv(
  pys=[2.7, 3.6, 3.9],
)