Step alias for JSON document.

spec/test/features/control/append/error_malformed.feature

@@ -8,7 +8,7 @@ Feature: Kapow! server reject append requests with malformed JSON bodies.
     the server will respond with a bad request error.
 
     Given I have a running Kapow! server
-    When I try to append with this JSON document:
+    When I try to append with this malformed JSON document:
       """
       {
         "method" "GET",

spec/test/features/steps/steps.py

@@ -167,6 +167,7 @@ def step_impl(context):
     raise NotImplementedError('STEP: When I insert the route')
 
 
+@when('I try to append with this malformed JSON document')
 @when('I try to append with this JSON document')
 def step_impl(context):
     raise NotImplementedError('STEP: When I try to append with this JSON document')