Fix: Upgrade JJB depencency to JJB_VERSION:6.0.0

Change-Id: I9c2616e1018acf17dbfe91c2e63e071b3a2f2a7c
Signed-off-by: Jessica Wagantall <jwagantall@linuxfoundation.org>
diff --git a/tox.ini b/tox.ini
index 72ca649..5eae10e 100644
--- a/tox.ini
+++ b/tox.ini
@@ -5,7 +5,7 @@
 
 [testenv:jenkins-jobs]
 deps =
-    jenkins-job-builder=={env:JJB_VERSION:5.1.0}
+    jenkins-job-builder=={env:JJB_VERSION:6.0.0}
 commands =
     jenkins-jobs {posargs:--help}