[ONOS-2794] Enable sending emails from main.stop()

    -Read email configuration from teston.cfg file
    -Make smtp parameters configurable

Change-Id: I7d8b412251a1a6f3e1a5eed39d0d9cd6937330d1
diff --git a/TestON/config/teston.cfg b/TestON/config/teston.cfg
index b255f45..aba93d1 100644
--- a/TestON/config/teston.cfg
+++ b/TestON/config/teston.cfg
@@ -5,6 +5,9 @@
         <class>xmlparser</class>
     </parser>
     <mail_to>hari@onlab.us</mail_to>
+    <mail_from></mail_from>
+    <mail_pass></mail_pass>
+    <mail_server></mail_server>
 
     <logger>
         <file>core/logger.py</file>