Remove "find_new_uid" script.

Mike pointed out that we already had functionality to do what it does,
so remove it and document existing functionality better.

BUG=None
TEST=None

Change-Id: Ief1ef6322cbf6a52c1ce8a2ba74e90e18eeee0c2
Reviewed-on: https://chromium-review.googlesource.com/1662545
Tested-by: Miriam Zimmerman <mutexlox@chromium.org>
Commit-Ready: ChromeOS CL Exonerator Bot <chromiumos-cl-exonerator@appspot.gserviceaccount.com>
Legacy-Commit-Queue: Commit Bot <commit-bot@chromium.org>
Reviewed-by: Mike Frysinger <vapier@chromium.org>
Reviewed-by: Jeffrey Kardatzke <jkardatzke@google.com>
diff --git a/profiles/base/accounts/README.md b/profiles/base/accounts/README.md
index efd623d..aedd483 100644
--- a/profiles/base/accounts/README.md
+++ b/profiles/base/accounts/README.md
@@ -53,7 +53,7 @@
 from 20100-29999. If you're creating a new user, pick the first UID in
 the range 20100-29999 that is not currently used, and create both a user
 and a group with this ID.  To find the next available UID, invoke
-`./find_new_uid.sh`.
+`./display-accts.py --show-free`.
 
 FUSE-based filesystem daemons have UID/GIDs that range from 300-399.
 If you're adding a daemon that will be talking to `cros-disks` and
diff --git a/profiles/base/accounts/find_new_uid.sh b/profiles/base/accounts/find_new_uid.sh
deleted file mode 100755
index 8fd0f0a..0000000
--- a/profiles/base/accounts/find_new_uid.sh
+++ /dev/null
@@ -1,9 +0,0 @@
-#!/bin/bash
-set -euo pipefail
-
-files="$(dirname $0)/user/*"
-echo -n "Your new UID is: "
-awk --field-separator : '
-  BEGIN { max = 20099 }
-  /^uid:/ { if ($2 <= 29999 && $2 > max) max = $2 }
-  END { print max + 1}' $files