Remove mass-assigment tests

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

spec/models/git_hook_spec.rb

@@ -5,10 +5,6 @@ describe GitHook do
     it { should belong_to(:project) }
   end
 
-  describe "Mass assignment" do
-    it { should_not allow_mass_assignment_of(:project_id) }
-  end
-
   describe "Validation" do
     it { should validate_presence_of(:project) }
   end

spec/models/project_group_link_spec.rb

@@ -6,11 +6,6 @@ describe ProjectGroupLink do
     it { should belong_to(:project) }
   end
 
-  describe "Mass assignment" do
-    it { should_not allow_mass_assignment_of(:group_id) }
-    it { should_not allow_mass_assignment_of(:project_id) }
-  end
-
   describe "Validation" do
     let!(:project_group_link) { create(:project_group_link) }