[release 0.1.19] Update changelog and docs (#543)

* [release 0.1.19] post and changelog

* Update exposed driver example to eventgrid

Author: zimengyang

CHANGELOG.md

@@ -3,15 +3,19 @@ All notable changes to this project will be documented in this file. For more in
 [What's New](https://vmware.github.io/dispatch/news) section on Dispatch website.
 
 
-## [Unreleased] - [[Git compare](https://github.com/vmware/dispatch/compare/v0.1.18...HEAD)]
+## [Unreleased] - [[Git compare](https://github.com/vmware/dispatch/compare/v0.1.19...HEAD)]
+
+### Added
+
+### Fixed
+
+## [0.1.19] - 2018-06-26 [[Git compare](https://github.com/vmware/dispatch/compare/v0.1.18...v0.1.19)] [[What's new](https://vmware.github.io/dispatch/2018/06/26/v0-1-19-release.html)]
 
 ### Added
 
 - **Enable Exposed Event Drivers** Events may now be pushed (as opposed to pulled) from event sources to Dispatch.  An *exposed*
 driver will create an ingress route and service to recieve events.
 
-### Fixed
-
 ## [0.1.18] - 2018-06-19 [[Git compare](https://github.com/vmware/dispatch/compare/v0.1.17...v0.1.18)] [[What's new](https://vmware.github.io/dispatch/2018/06/19/v0-1-18-release.html)]
 
 ### Fixed

docs/_posts/2018-06-26-v0-1-19-release.md

@@ -0,0 +1,59 @@
+---
+layout: post
+title: "v0.1.19 Dispatch Release"
+year: 2018
+---
+
+# v0.1.19 Dispatch Release
+
+[Download v0.1.19](https://github.com/vmware/dispatch/releases/tag/v0.1.19)
+
+
+## Support for Exposed Event Driver
+Events may now be pushed (as opposed to pulled) from event sources to Dispatch.  An *exposed* driver will create an ingress route and service to recieve events.
+When creating event driver type, use `--expose` to create exposed drivers, these drivers will have a URL which events can be pushed to.
+```bash
+$ dispatch create eventdrivertype eventgrid dispatchframework/events-eventgrid:0.0.1 --expose
+Created event driver type: eventgrid
+```
+The `EXPOSE` field of created event driver type should be true:
+```bash
+$ dispatch get eventdrivertype
+ NAME   |                IMAGE                 | EXPOSE
+-----------------------------------------------------------
+  eventgrid | dispatchframework/events-eventgrid:0.0.1 | true
+-----------------------------------------------------------
+```
+Next, to create exposed driver:
+```bash
+$ dispatch create eventdriver eventgrid --name eventgrid
+Created event driver: eventgrid
+```
+And After the driver was created successfully, we should see an URL:
+```bash
+$ dispatch get eventdriver
+    NAME    |   TYPE    | STATUS | SECRETS | CONFIG |                  URL                    | REASON
+-------------------------------------------------------------------------------------------------------
+  eventgrid | eventgrid | READY  |         |        | https://example.com/driver/dispatch/... |
+-------------------------------------------------------------------------------------------------------
+```
+and we can push events to this URL which the event driver will receive and process:
+```bash
+$ curl -i https://example.com/driver/dispatch/... -H 'Content-Type: application/cloudevents+json' -d @event.json
+HTTP/2 200
+server: nginx/1.13.12
+date: Tue, 26 Jun 2018 17:53:54 GMT
+content-length: 0
+strict-transport-security: max-age=15724800; includeSubDomains
+```
+
+
+## Update to Support Latest Cloud Event Implementation
+Dispatch now follows the latest [Cloud Events specification](https://github.com/cloudevents/spec/blob/a12b6b618916c89bfa5595fc76732f07f89219b5/spec.md)). `SourceType` and `EventType` were consolidated into one field, after the change, to add a new subscription for the `vm.being.created` event in a vcenter event driver, run:
+```bash
+$ dispatch create subscription --event-type vm.being.created myFunction
+```
+
+Detailed guide [Working with Events](https://vmware.github.io/dispatch/documentation/guides/working-with-events).
+
+