chronos-exporter: add aether-model 2.0.0

Change-Id: Id000163280e8af129e737169d2c434849186a54c
diff --git a/chronos-exporter/Chart.yaml b/chronos-exporter/Chart.yaml
index dca7932..bf1f827 100644
--- a/chronos-exporter/Chart.yaml
+++ b/chronos-exporter/Chart.yaml
@@ -7,8 +7,8 @@
 description: Chronos Exporter

 kubeVersion: ">=1.15.0"

 type: application

-version: 0.0.20

-appVersion: v0.0.17

+version: 0.0.21

+appVersion: v0.0.18

 keywords:

   - aether

   - exporter