NETWORK: Executed nping command with root privilege test_network_nping.robot

Changes:
    - In test_network_nping.robot added "echo ${root_password} | sudo -S" to the nping command and added ${CLIENT_PASSWORD} in resource.robot
Tested:
    - Ran network/test_network_nping.robot script Successfully

Change-Id: Ie7494e63eddaa31b76872067b657ed3c7385a64b
Signed-off-by: manimozhik <manimozhik@ami.com>
diff --git a/lib/resource.robot b/lib/resource.robot
index 44012a7..97440d4 100755
--- a/lib/resource.robot
+++ b/lib/resource.robot
@@ -168,6 +168,8 @@
 # 2 NTP Address - 14.139.60.103  14.139.60.106
 @{NTP_SERVER_ADDRESSES}    ${EMPTY}
 
+# Client related parameters
+${CLIENT_PASSWORD}         ${EMPTY}
 
 # Task Service related variables.
 ${TASK_JSON_FILE_PATH}   data/task_state.json