DMAP-26 - Provide necessary changes to the BrowserMap module for migration to ASF infrastructure

* updated Travis CI config file to use the trunk branch
* updated README.md to remove migration notice and provide new demo URL

git-svn-id: https://svn.apache.org/repos/asf/incubator/devicemap/trunk/browsermap/trunk@1507109 13f79535-47bb-0310-9956-ffa450edef68