Use buck for tests

- use buck instead of maven
- cleanup output when building cluster.json file
- swap the correct nodes in swap nodes test

(cherry picked from commit 4b66b32e5057d84175195a9c5a823e59cb66fa67)

Change-Id: If5981567115fd3acdc353f4a2ee620f5e0a29716
diff --git a/TestON/tests/CHO/CHOtest/CHOtest.py b/TestON/tests/CHO/CHOtest/CHOtest.py
index 94990c3..27104b8 100644
--- a/TestON/tests/CHO/CHOtest/CHOtest.py
+++ b/TestON/tests/CHO/CHOtest/CHOtest.py
@@ -109,7 +109,7 @@
         main.ONOSbench.getVersion( report=True )
 
         main.step( "Create ONOS package" )
-        packageResult = main.ONOSbench.onosPackage()
+        packageResult = main.ONOSbench.buckBuild()
         utilities.assert_equals( expect=main.TRUE, actual=packageResult,
                                  onpass="Test step PASS",
                                  onfail="Test step FAIL" )