Svut Versions Save

New release providing Pypi distribution and misc. fixes

Full Changelog: https://github.com/dpretet/svut/compare/v1.6.0...v1.6.1

Misc. updates for this new iteration:

• pass to python 3 and clean the code
• rely in python template engine for SystemVerilog and cpp generated files
• add more information in README
• move to GitHub Actions and enhance the regression scope
• start a first support of Verilator. Execution is OK, needs to enhance cpp template and prepare a svut.h to bring equivalent SystemVerilog macros in C++ world. Will be probably minimal and based on existing unit test flow

A minor release to print SVUT version, start and stop time of the execution