adding unit tests for lexer `prettyPrintRange()` API to better cover https://github.com/GerHobbelt/jison/issues/20 and check https://github.com/GerHobbelt/jison/issues/19 regression.
adding unit tests for lexer `prettyPrintRange()` API to better cover https://github.com/GerHobbelt/jison/issues/20 and check https://github.com/GerHobbelt/jison/issues/19 regression.

GerHobbelt/jison,GerHobbelt/jison,GerHobbelt/jison,GerHobbelt/jison