Fixing TT 2.7 job by checking out correct voltha-system-tests and podconfigs

Change-Id: I16cedc53735b8be8c28a94df420358cda1b6d110
diff --git a/VERSION b/VERSION
index a603bb5..49cdd66 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-2.7.5
+2.7.6