Use UTF-8 encoding to read long description in setup.py

[koenvervloesem]

Description:

This fixes issue #97 by making the encoding explicit when reading the long description of the package in setup.py. When not set explicitly, Windows uses cp1252 encoding and installation of the package fails.

Checklist:

• The pull request is done against the latest development branch
• Only one feature/fix was added per PR and the code change compiles without warnings
• I accept the DCO.

[1technophile]

Thanks