Unable to import ccp from pyccp

As the pyccp directory is not included in the package's path it is not possible to reference the ccp, master or slave modules in order to create custom masters and slaves with other transport protocols than the mock. The only included directory in setup is tests and `__init__.py` files are empty.

https://github.com/pySART/pyccp/blob/87203eda328598c76460989abe594a33b7cc831f/setup.py#L28C2-L28C2