Update README build badges.
<table>
<tr>
- <td><strong>Linux / OS X</strong></td>
+ <td><strong>Linux / OS X stable</strong></td>
+ <td><a href="https://dev.azure.com/matthewkmayer/Rusoto/_build?definitionId=1" title="Pipelines Build Status"><img src="https://dev.azure.com/matthewkmayer/Rusoto/_apis/build/status/rusoto.rusoto?branchName=master" alt="pipelines-badge"></img></a></td>
+ </tr>
+ <tr>
+ <td><strong>Linux / OS X beta and nightly</strong></td>
<td><a href="https://travis-ci.org/rusoto/rusoto" title="Travis Build Status"><img src="https://travis-ci.org/rusoto/rusoto.svg?branch=master" alt="travis-badge"></img></a></td>
</tr>
<tr>
