Update defaults for mininet and ponsimv2 charts

Change-Id: I750dcf7edee64a23292227bab44a3d977f43e0b9
diff --git a/mininet/Chart.yaml b/mininet/Chart.yaml
index 9619440..511a649 100644
--- a/mininet/Chart.yaml
+++ b/mininet/Chart.yaml
@@ -17,4 +17,4 @@
 appVersion: "1.0"
 description: A Helm chart for Mininet
 name: mininet
-version: 0.5.1
+version: 0.5.2