Add aborted message_spec

Author: glentakahashi

ipykernel/tests/test_message_spec.py

@@ -114,6 +114,8 @@ def check(self, d):
             ExecuteReplyOkay().check(d)
         elif d['status'] == 'error':
             ExecuteReplyError().check(d)
+        elif d['status'] == 'aborted':
+            ExecuteReplyAborted().check(d)
 
 
 class ExecuteReplyOkay(Reply):
@@ -122,11 +124,16 @@ class ExecuteReplyOkay(Reply):
 
 
 class ExecuteReplyError(Reply):
+    status = Enum(('error',))
     ename = Unicode()
     evalue = Unicode()
     traceback = List(Unicode())
 
 
+class ExecuteReplyAborted(Reply):
+    status = Enum(('aborted',))
+
+
 class InspectReply(Reply, MimeBundle):
     found = Bool()