Workflow or item not found now return 404

lib/scriptoria-core/application.rb

@@ -50,7 +50,7 @@ class Application < Grape::API
         end
 
         rescue_from Workflow::NotFoundError do |e|
-          error!('workflow_id not found', 400)
+          error!('workflow_id not found', 404)
         end
 
         post :cancel do
@@ -69,7 +69,7 @@ class Application < Grape::API
             end
 
             rescue_from Workitem::NotFoundError do |e|
-              error!('workitem_id not found', 400)
+              error!('workitem_id not found', 404)
             end
 
             rescue_from Workitem::WorkflowMismatchError do |e|

spec/requests/v1/workflow_cancel_spec.rb

@@ -21,12 +21,12 @@
     end
 
     context "validations" do
-      it "returns an error if the workflow does exist" do
+      it "returns an error if the workflow does not exist" do
         allow(ScriptoriaCore::Workflow).to receive(:cancel!).and_raise(ScriptoriaCore::Workflow::NotFoundError)
 
         post '/v1/workflows/1234/cancel'
 
-        expect(response.status).to eq 400
+        expect(response.status).to eq 404
         expect(response.body).to   eq '{"error":"workflow_id not found"}'
       end
     end

spec/requests/v1/workitem_proceed_spec.rb

@@ -56,7 +56,7 @@
           }
         }
 
-        expect(response.status).to eq 400
+        expect(response.status).to eq 404
         expect(response.body).to   eq '{"error":"workitem_id not found"}'
       end