Update shields.io docker build status URL

Author: rroemhild

README.md

@@ -1,6 +1,6 @@
 # OpenLDAP Docker Image for testing
 
-![Docker Build Status](https://img.shields.io/docker/build/rroemhild/test-openldap.svg) ![Docker Stars](https://img.shields.io/docker/stars/rroemhild/test-openldap.svg) ![Docker Pulls](https://img.shields.io/docker/pulls/rroemhild/test-openldap.svg)
+![Docker Build Status](https://img.shields.io/docker/cloud/build/rroemhild/test-openldap) ![Docker Stars](https://img.shields.io/docker/stars/rroemhild/test-openldap.svg) ![Docker Pulls](https://img.shields.io/docker/pulls/rroemhild/test-openldap.svg)
 
 This image provides an OpenLDAP Server for testing LDAP applications, i.e. unit tests. The server is initialized with the example domain `planetexpress.com` with data from the [Futurama Wiki][futuramawikia].