build-env: change /usr/bin/etcdctl to etcdctl

Author: Dongsu Park

build-env

@@ -21,4 +21,5 @@ eval $(go env)
 export PATH="${GOROOT}/bin:${PATH}"
 export FLEETD_BIN="$(pwd)/bin/fleetd"
 export FLEETCTL_BIN="$(pwd)/bin/fleetctl"
-export ETCDCTL_BIN="/usr/bin/etcdctl"
+#export ETCDCTL_BIN="/usr/bin/etcdctl"
+export ETCDCTL_BIN="etcdctl"