* migrate
* abstract base class test
* remove assert_equal in test_cli
* remove nose from test_cli
* remove nose dependencies
* use tempfile
* configure coverage
* flag python version in name
* enable comment
* drop EOL py37
Add Function to Dummy Printer for Clearing Buffer
If you are using the dummy printer, you may want to use the printer
again after sending the output to a physical printer.
This method empties the list of the output buffer.