POT BOOM: Less Cheech and Chong and more doctors and lawyers at medical marijuana expo in Pennsylvania

Editor’s note: This is the first in a series of stories on medical cannabis and how its legalization will impact Pennsylvanians.

PITTSBURGH >> It’s been a year since Gov. Tom Wolf signed the bill making medical marijuana legal in Pennsylvania – planting the seeds of capitalism in a new industry.

Now one of the biggest signs that this industry could be about to explode was seen Friday along the banks of the…