Add go-vitotrol, Viessmann Vitotrol ws client (#1252)

* Add go-vitotrol, Viessmann Vitotrol ws client

Please check if what you want to add to `awesome-go` list meets [quality standards](https://github.com/avelino/awesome-go/blob/master/CONTRIBUTING.md#quality-standard) before sending pull request. Thanks!

**Please provide package links to:**
- github.com repo: https://github.com/maxatome/go-vitotrol
- godoc.org: https://godoc.org/github.com/maxatome/go-vitotrol
- goreportcard.com: https://goreportcard.com/report/github.com/maxatome/go-vitotrol
- coverage service link (gocover, coveralls etc.): https://gocover.io/github.com/maxatome/go-vitotrol


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**Make sure that you've checked the boxes below before you submit PR:**
- [x] I have added my package in alphabetical order
- [x] I know that this package was not listed before
- [x] I have added godoc link to the repo and to my pull request
- [x] I have added coverage service link to the repo and to my pull request
- [x] I have added goreportcard link to the repo and to my pull request
- [x] I have read [Contribution guidelines](https://github.com/avelino/awesome-go/blob/master/CONTRIBUTING.md#contribution-guidelines) and [Quality standard](https://github.com/avelino/awesome-go/blob/master/CONTRIBUTING.md#quality-standard).

Thanks for your PR, you're awesome! 👍

* Reorder go-vitotrol

The hyphen counts !

README.md

@@ -623,6 +623,7 @@ See [go-hardware](https://github.com/rakyll/go-hardware) for a comprehensive lis
 * [go-longpoll](https://github.com/ventu-io/go-longpoll) - PubSub with long polling.
 * [go-notify](https://github.com/TheCreeper/go-notify) - Native implementation of the freedesktop notification spec.
 * [go-nsq](https://github.com/nsqio/go-nsq) - the official Go package for NSQ
+* [go-vitotrol](https://github.com/maxatome/go-vitotrol) - A client library to Viessmann Vitotrol web service.
 * [gopush-cluster](https://github.com/Terry-Mao/gopush-cluster) - gopush-cluster is a go push server cluster.
 * [gorush](https://github.com/appleboy/gorush) - A push notification server using [APNs2](https://github.com/sideshow/apns2) and google [GCM](https://github.com/google/go-gcm).
 * [guble](https://github.com/smancke/guble) - A messaging server using push notifications (Google Firebase Cloud Messaging, Apple Push Notification services, SMS) as well as websockets, a REST API, featuring distributed operation and message-persistence.