watch: convert TestKeyWatch to use channels
watch: convert TestKeyWatch to use channels

kingland/consul,hashicorp/consul,kingland/consul,calgaryscientific/consul,calgaryscientific/consul,i0rek/consul,hashicorp/consul,calgaryscientific/consul,hashicorp/consul,youhong316/consul,scalp42/consul,scalp42/consul,calgaryscientific/consul,vamage/consul,youhong316/consul,scalp42/consul,i0rek/consul,i0rek/consul,42wim/consul,42wim/consul,calgaryscientific/consul,vamage/consul,i0rek/consul,youhong316/consul,42wim/consul,kingland/consul,hashicorp/consul,scalp42/consul,i0rek/consul,42wim/consul,vamage/consul,youhong316/consul,vamage/consul,scalp42/consul,42wim/consul,kingland/consul,kingland/consul,youhong316/consul,vamage/consul