Juniper driver - fix NETCONF discovery of JUNOS v19 devices regarding chassis-mac-addresses RPC

Added UT based on XML responses from v15 and v19 devices

Change-Id: Id4e0fe34b12dea6034e75f2276495282ea2e6aa2
diff --git a/drivers/juniper/src/test/resources/Junos_get-chassis-mac-addresses_response_15.1.xml b/drivers/juniper/src/test/resources/Junos_get-chassis-mac-addresses_response_15.1.xml
new file mode 100644
index 0000000..8c6c8ff
--- /dev/null
+++ b/drivers/juniper/src/test/resources/Junos_get-chassis-mac-addresses_response_15.1.xml
@@ -0,0 +1,10 @@
+<?xml version="1.0"?>
+<rpc-reply xmlns:junos="http://xml.juniper.net/junos/15.1R5/junos" xmlns="urn:ietf:params:xml:ns:netconf:base:1.0" message-id="1">
+    <output>
+        MAC address information:
+        Public base address     84:18:88:99:7c:00
+        Public count            1984
+        Private base address    84:18:88:99:83:c0
+        Private count           64
+    </output>
+</rpc-reply>
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