cmd/coordinator-cli: do not convert json numbers to float
cmd/coordinator-cli: do not convert json numbers to float

encoding/json treats json numbers as float when the target is interface{},
when coordinator-cli hands that to acomm it gets encoded as a float which can
not be parsed as a time.Duration (int64).

cerana/cerana,cerana/cerana,cerana/cerana,cerana/cerana