Merge pull request #726 from msmolens/test-status-link

STYLE: Fix CircleCI link

README.rst

@@ -1,8 +1,8 @@
 Common Toolkit
 ==============
 
-.. image:: https://circleci.com/gh/commontk/CTK.svg?style=svg
-    :target: http://my.cdash.org/index.php?project=CTK
+.. image:: https://circleci.com/gh/commontk/CTK.png?style=shield
+    :target: https://circleci.com/gh/commontk/CTK
 
 The Common Toolkit is a community effort to provide support code for medical image analysis,
 surgical navigation, and related projects.