MILWAUKEE (AP) – Gov. Scott Walker says he challenged his fellow governors to join him for a motorcycle ride when the National Governors Association meets in Milwaukee this summer.  Walker says Wisconsin will pay for the other governors to take training courses to ride Harley-Davidson motorcycles.  Walker told reporters Tuesday several governors have already agreed to learn how to ride a motorcycle, and two others who already ride have accepted his invitation.  The NGA includes all 50 governors. The group’s 2013 meeting will take place in Milwaukee from Aug. 2 to Aug. 4.  Other plans for the meeting include having the governors take batting practice at Miller Park before the Milwaukee Brewers open a series against the Washington Nationals.   Wisconsin last hosted an annual meeting of the NGA in 1998.