WASHINGTON (Reuters) - Presumptive Republican presidential nominee Donald Trump and U.S. House of Representatives Speaker Paul Ryan said on Thursday they had taken a “positive step” toward unifying the Republican Party with the goal of winning the White House in November. “With that focus, we had a great conversation this morning. While we were honest about our few differences, we recognize that there are also many important areas of common ground,” the two said in a joint statement.  “This was our first meeting, but it was a very positive step toward unification,” the statement said. 