Security measures for the US Republican Party convention and for Donald Trump have been stepped up following the assassination attempt on the former president. Planning for the security of the meeting in Milwaukee in the US state of Wisconsin has been “reviewed and strengthened” following the assassination attempt on Saturday, said the director of the secret service, Kimberly Cheatle. The agency is responsible for protecting the occupant of the White House and former presidents. It was criticized after Saturday’s assassination attempt, in which a gunman shot at Trump from a nearby rooftop duri…