Linux formula should be able to create non-unique users.

Change-Id: I3338950ed3726a750149d849d33813b0eeed50c0
diff --git a/tests/pillar/system.sls b/tests/pillar/system.sls
index 43fc65c..de1da29 100644
--- a/tests/pillar/system.sls
+++ b/tests/pillar/system.sls
@@ -137,6 +137,7 @@
         uid: 9999
         full_name: Test User
         home: /home/test
+        unique: false
         groups:
           - db-ops
           - salt-ops