Bump Chronograf (#3187)

stable/chronograf/Chart.yaml

 name: chronograf
-version: 0.3.0
+version: 0.4.0
 description: Open-source web application written in Go and React.js that provides
   the tools to visualize your monitoring data and easily create alerting and automation
   rules.

stable/chronograf/values.yaml

 ## Image Settings
 ##
 image:
-  repository: "quay.io/influxdb/chronograf"
-  tag: "latest"
+  repository: "docker.io/chronograf"
+  tag: "1.3-alpine"
   pullPolicy: "Always"
 
 ## Specify a service type
@@ -70,7 +70,8 @@ oauth:
     enabled: false
     client_id: CHANGE_ME
     client_secret: CHANGE_ME
-    public_url: "" # eg. http://chronograf.foobar.com
+    # eg. http://chronograf.foobar.com
+    public_url: ""
     # This is a comma seperated list of Google Apps domains (OPTIONAL)
     google_domains: ""
   heroku: