v0.6.1

• Make tests with tox pass again so release can be automatically deployed:
  • Add Black reformatter to tox linter envs
  • Tox config: new linters env to run Flake8
  • Tox config update: Flake8 against tests/ and setup.py as well
  • Make xled.compat pass Flake8 for F821 undefined names
  • Refactor beacon processing of seen/new peer into separate methods
  • Reformat test_control test with black
  • Make tox install test-only requires
  • Use conditional deployment to pypi with travis only from master