Several members of the Pentagon's Defense Business Board, including the chair and vice chair, were fired on Friday, marking the latest effort by the Trump administration to clean out the Defense Department in the final weeks of the president's term, according to three former board members.Members of the board received a brief email from Joshua Whitehouse, the White House liaison to the Department of Defense, that simply said, “if you are receiving this e-mail, your membership on the Defense Business Board has expired or is coming to an end.”The three board members who spoke to POLITICO said their tours were...