add remove_items from collection test

spec/acceptance/collections_spec.rb

@@ -70,6 +70,27 @@ resource 'Collections' do
     end
   end
 
+  delete '/v1/collections/:id/items' do
+    include_context "authenticate_user"
+
+    parameter :items, 'Items belongs to the collection', scope: :collection
+
+    let(:id) { @collection.id }
+    let(:items) { [ { id: @collection_item.id } ] }
+    let(:raw_post) { params.to_json }
+
+    before do
+      @collection = create(:collection, owner: @user)
+      @collection_item = create(:collection_item, collection: @collection)
+    end
+
+    example 'Remove items from collection' do
+      do_request
+      expect(status).to eq(200)
+    end
+
+  end
+
 
   post '/v1/collections/:id/like' do
     include_context "authenticate_user"

spec/factories/collection_items.rb

+FactoryGirl.define do
+  factory :collection_item do
+    collection
+    collectionable
+    position { rand(0..10) }
+  end
+end