Parameterized Environment Variables

[import-au]

Is your feature request related to a problem? Please describe.
Maldocs are often keyed using environment variables. Would be nice to have the ability to pass a parameter to ViperMonkey to set these environment variables on execution.

Describe the solution you'd like
Thinking something like vmonkey.py -E USERDNSDOMAIN=example.com

Describe alternatives you've considered
I could hardcode my own versions every time I want to try and boot it up.

Additional context
SPACE CAT!!! I might grab this FR and submit a PR, but I at least wanted to get this filed so it wasn't lost.