Wait for cleanup to be done after stop VMM

[Joffref]

trafficstars

Closes: #428

Description of changes: add a cleanup chan to ensure cleanup is waited by the stopVMM method.

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

Signed-off-by: Sugate [email protected]

[ginglis13]

Hi @Joffref , thanks for the PR! Could you please add DCO to your commits by signing them git commit -s?

[ginglis13]

LGTM, thanks. 2 quick requests before we can merge this:

1/ Can you squash these 5 commits into one commit?

2/ Can you sign that commit using your full, real first and last name?