moving code into conventional Python project structure.  Will also distribute test code with API, so can be used to write apps to test users completed board kits
deleting last part of separate test source dir
pytest config
delete more junk in make clean
retire I2C loopback tests that rely on the MCP23008, since we now have tests that use the Q2W MCP23017 board
Made README and examples reflect new GPIO pin classes and Pythonic project structure.  GPIO works with epoll again (bug fix)