Using latest BBSim chart by default

Change-Id: I3ebb2f968eda8aec3a1c254cf8bfd0d3ce52cd9d
diff --git a/voltha b/voltha
index 708429a..8e9ddb0 100755
--- a/voltha
+++ b/voltha
@@ -110,7 +110,7 @@
 VOLTHA_CHART=${VOLTHA_CHART:-onf/voltha}
 VOLTHA_CHART_VERSION=${VOLTHA_CHART_VERSION:-latest}
 VOLTHA_BBSIM_CHART=${VOLTHA_BBSIM_CHART:-onf/bbsim}
-VOLTHA_BBSIM_CHART_VERSION=${VOLTHA_BBSIM_CHART_VERSION:-4.0.0-dev}
+VOLTHA_BBSIM_CHART_VERSION=${VOLTHA_BBSIM_CHART_VERSION:-latest}
 ELASTICSEARCH_CHART=${ELASTICSEARCH_CHART:-elastic/elasticsearch}
 ELASTICSEARCH_CHART_VERSION=${ELASTICSEARCH_CHART_VERSION:-latest}
 KIBANA_CHART=${KIBANA_CHART:-elastic/kibana}