0.80.2 RC

New http client (#127)

* Refactor the http client

* Temporary remove IoT-Cognitive

* refactor http_client

* Add test sample

* Stabled

* fix merge conflict

* update the HttpTest

* fix build for VoiceToTwitter

* minor fix

0.80.1 RC

Improve the user experience of the Azure IoT hub demo app. (#87)

* Improve the user experience of the Azure IoT hub demo app.
Fix the issue of  telemetry.

* Move all function tests to upper level directory

* Fix merge issue

* Add heartbeat