README: add Azure Pipelines

Also put all three CI badges on same line

README.md

@@ -2,9 +2,7 @@
 
 [![Gitter](https://badges.gitter.im/Join%20Chat.svg)](https://gitter.im/ArduPilot/ardupilot?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)
 
-[![Build SemaphoreCI](https://semaphoreci.com/api/v1/ardupilot/ardupilot/branches/master/badge.svg)](https://semaphoreci.com/ardupilot/ardupilot)
-
-[![Build Travis](https://travis-ci.org/ArduPilot/ardupilot.svg?branch=master)](https://travis-ci.org/ArduPilot/ardupilot)
+[![Build Travis](https://travis-ci.org/ArduPilot/ardupilot.svg?branch=master)](https://travis-ci.org/ArduPilot/ardupilot) [![Build SemaphoreCI](https://semaphoreci.com/api/v1/ardupilot/ardupilot/branches/master/badge.svg)](https://semaphoreci.com/ardupilot/ardupilot) [![Build Status](https://dev.azure.com/ardupilot-org/ardupilot/_apis/build/status/ArduPilot.ardupilot?branchName=master)](https://dev.azure.com/ardupilot-org/ardupilot/_build/latest?definitionId=1&branchName=master)
 
 [![Coverity Scan Build Status](https://scan.coverity.com/projects/5331/badge.svg)](https://scan.coverity.com/projects/ardupilot-ardupilot)