TBR: ref: namespace_browser: Move v.io/x/ref/tools to v.io/x/ref/cmd.

This is part of the v.io reorganization.  cmd is the standard
go directory for commandline binaries.  We actually have two:
cmd for regular command line tools, and services for servers.

Note, I am temporarily duplicating the vdl tool for ease of transition.

MultiPart: 4/8

Change-Id: I1880ea23f643b60d315b14e2695c63932fe99625
diff --git a/lib/testutil/v23tests/v23tests_test.go b/lib/testutil/v23tests/v23tests_test.go
index 480ad07..64ceb99 100644
--- a/lib/testutil/v23tests/v23tests_test.go
+++ b/lib/testutil/v23tests/v23tests_test.go
@@ -48,7 +48,7 @@
 
 	v23tests.RunRootMT(env, "--veyron.tcp.address=127.0.0.1:0")
 	proxyBin := env.BuildGoPkg("v.io/x/ref/services/proxy/proxyd")
-	nsBin := env.BuildGoPkg("v.io/x/ref/tools/namespace")
+	nsBin := env.BuildGoPkg("v.io/x/ref/cmd/namespace")
 
 	mt, ok := env.GetVar("NAMESPACE_ROOT")
 	if !ok || len(mt) == 0 {