[ensure] Add lucicfg tool.

It's a new tool being developed by Chrome Ops team.
Initially we'll use it to validate our existing configs.

Test: ran update.sh and then ran the lucicfg tool
Bug: INTK-296 #comment
Change-Id: I0f841ecdeb1dc8c3114b38af83ae100af3154cfd
diff --git a/cipd.ensure b/cipd.ensure
index 032b3ea..2de8116 100644
--- a/cipd.ensure
+++ b/cipd.ensure
@@ -29,5 +29,8 @@
 # LogDog CLI client
 infra/tools/luci/logdog/logdog/${platform} git_revision:2237a617181dbfcee8b37f94a5b7d834f0f69fb0
 
+# Lucicfg tool
+infra/tools/luci/lucicfg/${platform}  git_revision:945172c134b5bfd42d4ac5edce3cb681d26dc75f
+
 # vpython
 infra/tools/luci/vpython/${platform} git_revision:2237a617181dbfcee8b37f94a5b7d834f0f69fb0