Add more cleanup to mininet driver

Change-Id: I5a794b4cbd9456f8b8010b24f9ed564845fc9a58
diff --git a/TestON/drivers/common/cli/emulator/mininetclidriver.py b/TestON/drivers/common/cli/emulator/mininetclidriver.py
index 1da21b9..0446e2c 100644
--- a/TestON/drivers/common/cli/emulator/mininetclidriver.py
+++ b/TestON/drivers/common/cli/emulator/mininetclidriver.py
@@ -2390,6 +2390,10 @@
                     main.log.error( "Something went wrong exiting mininet " +
                                     "TIMEOUT" )
 
+                self.handle.sendline( "" )
+                self.handle.expect( self.prompt )
+                self.handle.sendline( "sudo killall -9 dhclient dhcpd zebra bgpd" )
+
                 if fileName:
                     self.handle.sendline( "" )
                     self.handle.expect( self.prompt )