tell setuptools to install using a valid module name

[greyltc]

• [x] Closes #216 #253 #239
• [ ] Executed black . && isort -c . && flake8 with no errors
• [x] The change is fully covered by automated unit tests
• [x] Documented in docs/ as appropriate
• [x] Added an entry to the CHANGES file

[MatthieuDartiailh]

This PR does something different than intended by renaming the overall project to pyvisa_py which is not the solution proposed in #239. See https://github.com/pyvisa/pyvisa-py/issues/253#issuecomment-687666704 for more details