Updated reboot, shutdown and halt rpc calls for WR-Linux HW.

[rsmekala]

• Addresses Juniper Junos System - Reboot fails on WR Linux Based Hardware QFX5200  #383 , No check for other RE in case of WR Linux Based Hardware QFX 5200 #385.

[vnitinv]

@rsmekala Check why travis is failing.

[mamathac]

Verified the fix on Local report code version and found to be working.
Please merge with master before we close.

`PLAY [Testing Juniper Junos Core Modules] ************************************************************************************************************************************************************

TASK [Reboot all REs of the device] ******************************************************************************************************************************************************************
changed: [ROUTER]

PLAY RECAP *******************************************************************************************************************************************************************************************
ROUTER : ok=1 changed=1 unreachable=0 failed=0
`

---

Broadcast message from root@ROUTER (somewhere) (Tue Oct 2 23:39:47 201

System going down IMMEDIATELY