
 0.01  2017-07-08

       Start on initial version.

 0.02  2017-07-12

       Add VERSION to Edge.pm, Label.pm and Node.pm.

 0.03  2017-07-13

       Method same_rank() in GraphViz::Graph

       Allow for subclassing Graph.pm and Node.pm

       Check if dot is installed in Makefile.pl
       sub is_dot_installed() {...}
