ArtifactSupportNamespaceHandler no longer exists.

This was used for Taverna 2 Raven spring extensions
diff --git a/taverna-reference-impl/src/main/resources/META-INF/spring.handlers b/taverna-reference-impl/src/main/resources/META-INF/spring.handlers
deleted file mode 100644
index f3bed57..0000000
--- a/taverna-reference-impl/src/main/resources/META-INF/spring.handlers
+++ /dev/null
@@ -1 +0,0 @@
-http\://taverna.sf.net/schema/artifact-support=org.apache.taverna.platform.spring.ArtifactSupportNamespaceHandler
\ No newline at end of file