Update conf.py
Update conf.py

Added creation of PID_DIR in case the pidfile is not found and the PID_DIR doesn´t exist. Under normal circumstances, it should only execute on the first run of carbon.
criteo-forks/carbon,mleinart/carbon,JeanFred/carbon,graphite-project/carbon,mleinart/carbon,lyft/carbon,krux/carbon,kharandziuk/carbon,obfuscurity/carbon,iain-buclaw-sociomantic/carbon,cbowman0/carbon,iain-buclaw-sociomantic/carbon,deniszh/carbon,obfuscurity/carbon,benburry/carbon,pratX/carbon,benburry/carbon,kharandziuk/carbon,johnseekins/carbon,pu239ppy/carbon,JeanFred/carbon,criteo-forks/carbon,graphite-project/carbon,deniszh/carbon,graphite-server/carbon,johnseekins/carbon,krux/carbon,piotr1212/carbon,pu239ppy/carbon,piotr1212/carbon,xadjmerripen/carbon,graphite-server/carbon,cbowman0/carbon,xadjmerripen/carbon,pratX/carbon,lyft/carbon