Switched logo from SVG to PNG for compatibility reasons.

README.md

@@ -1,4 +1,4 @@
-<img src="https://cdn.rawgit.com/witten/borgmatic/master/static/borgmatic.svg" width="150px" style="float: right; padding-left: 1em;">
+<img src="static/borgmatic.png" width="150px" style="float: right; padding-left: 1em;">
 
 ## Overview