Fix the link to Appveyor and use SVG images.
-[![Travis Build Status](https://travis-ci.org/warmcat/libwebsockets.png)](https://travis-ci.org/warmcat/libwebsockets)
-[![Appveyor Build status](https://ci.appveyor.com/api/projects/status/qfasji8mnfnd2r8t)](https://ci.appveyor.com/project/warmcat/libwebsockets)
+[![Travis Build Status](https://travis-ci.org/warmcat/libwebsockets.svg)](https://travis-ci.org/warmcat/libwebsockets)
+[![Appveyor Build status](https://ci.appveyor.com/api/projects/status/qfasji8mnfnd2r8t?svg=true)](https://ci.appveyor.com/project/lws-team/libwebsockets)
[![Coverity Scan Build Status](https://scan.coverity.com/projects/3576/badge.svg)](https://scan.coverity.com/projects/3576)
libwebsockets