Kicked out of school for fighting, again, 15-year-old Cole (Caleb McLaughlin of “Stranger Things”) doesn’t know what to expect when his exasperated mom drives him to Philadelphia and drops the hotheaded teen on his estranged father’s doorstep for the summer, but the last thing he expects to find in the living room is a horse. Cole can hardly remember his dad, so he has no idea the guy spends most of his time around the corner at the Fletcher Street Stables, playing modern-day cowboy. Then again, who can blame the kid: How many people realize there’s such a thing as inner-city equestrians, much less remember the role Black men have played in American horsemanship?