Billionaire entrepreneur Elon Musk publicly defended himself against allegations of drug use, taking to Twitter to criticize the Wall Street Journal’s reporting. What Happened: Musk, in a post on Sunday, said he had agreed to undertake three years of random drug testing at the behest of NASA, with no traces of any drugs or alcohol found. “After that one puff with [Joe] Rogan, I agreed, at NASA’s request, to do 3 years of random drug testing. Not even trace quantities were found of any drugs or alcohol,” Musk said, reacting to a series of posts about the report. “@WSJ is not fit to line a parro…