Update URL in README.rst to reflect move from rlsosborne to xcore

Author: Richard Osborne

Diff for: README.rst

@@ -9,8 +9,8 @@ AXE (An XCore Emulator)
 
 :Description: AXE is a fast open source simulator of the XMOS XS1 Architecture.
 
-.. image:: https://travis-ci.org/rlsosborne/tool_axe.svg?branch=master
-    :target: https://travis-ci.org/rlsosborne/tool_axe
+.. image:: https://travis-ci.org/xcore/tool_axe.svg?branch=master
+    :target: https://travis-ci.org/xcore/tool_axe
     :alt: Build Status
 
 AXE is designed for fast simulation of XCore programs. AXE doesn't attempt to