0.2.7 branch (#165)

* updating black  due to incompatibility with Click (#144)

* Security upgrade mkdocs from 1.2.3 to 1.3.0 (#146)

* update README with links to docs (#148)

* Fixes KeyError due to unavailable options for dynamips (#151)

* Fixes lab deletion with empty nodes (#153)

* Clean up broken tests

* move shared fixtures
* fix failing tests
* Adds pytest config

* Fix tracebacks in CLI output

* clean up tracebacks for lab commands

* clean up tracebacks for node commands

* clean up tracebacks for system commands

* clean up tracebacks for user commands

* Adds tempate for topo builder test

* fix linting errors

* clean up old files

* Adds mkdoc docs

* Adds docs directory

* Bump version to 0.2.7