Fix Codeclimate badge

Author: schmengler

README.md

@@ -8,7 +8,7 @@
 
 [![Coverage Status][ico-scrutinizer]][link-scrutinizer]
 [![Quality Score][ico-code-quality]][link-code-quality]
-[![Maintainability](ico-maintenability)](link-maintainability)
+[![Maintainability][ico-maintainability]][link-maintainability]
 </div>
 
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