NEW YORK -- Steve Coll is stepping down as dean of the Columbia University Journalism School next June, saying that he will continue teaching there after nine years leading one of the nation's top training grounds for reporters.Coll was behind the creation of a new master's degree in data journalism, and the creation of centers for global journalism, civil and human rights and the fighting of disinformation, the university's president, Lee Bollinger, said Thursday.“Steve’s life experiences gave