fix tests

app/models/project.rb

@@ -491,8 +491,10 @@ class Project < ActiveRecord::Base
     hooks.send(hooks_scope).each do |hook|
       hook.async_execute(data)
     end
-    group.hooks.send(hooks_scope).each do |hook|
-      hook.async_execute(data)
+    if group
+      group.hooks.send(hooks_scope).each do |hook|
+        hook.async_execute(data)
+      end
     end
   end
 

spec/services/test_hook_service_spec.rb

 require 'spec_helper'
 
 describe TestHookService do
-  let (:user)    { create :user }
-  let (:group)   { create :group }
-  let (:project) { create :project, group: group }
-  let (:project_hook)    { create :project_hook, project: project }
-  let (:group_hook)    { create :group_hook, group: group }
+  let (:user)        { create :user }
+  let (:group)       { create :group }
+  let (:project)     { create :project, group: group }
+  let (:project_hook){ create :project_hook, project: project }
+  let (:group_hook)  { create :group_hook, group: group }
 
 
   describe :execute do