Use a goroutine with function arguments for ConcurrentAction (#1412)
Use a goroutine with function arguments for ConcurrentAction (#1412)

Summary: starting goroutines can potentially bleed implementation in a loop 
(since the loop values are changing).  This change in particular was probably NBD
but I ended up copying this code for another case and ended up shooting myself in the
foot, changing this code to save future selves.
yarpc/yarpc-go,yarpc/yarpc-go