step 2: add sudo check

Change-Id: I9688040ad619ca40ce96e6c3b5538c492373f510
diff --git a/deployment/step-2-site-ca.sh b/deployment/step-2-site-ca.sh
index 1a38c64..7d4029f 100644
--- a/deployment/step-2-site-ca.sh
+++ b/deployment/step-2-site-ca.sh
@@ -1,5 +1,11 @@
 #! /bin/bash
 
+# sudo check
+if [ "$EUID" -ne 0 ]
+  then echo "Please run as root"
+  exit
+fi
+
 echo 'Please enter the /ndn certificate:(end with Ctrl-D)'
 ROOT_CERT=$(cat | tr -d '\n')