Minor doc update

1.7.3 changelog

1.7.2 changelog

1.7.1 - pyproject.toml

Fixed one failing test

1.6.4 changelog

1.6.3 changelog

Fixed coverage command for travis

1.6.1 Made the python 3 signature patch more readable... for those us…

…ers who will enter in the code while debugging.

Added all new badges.