Remove unnecessary slash in curl command (#349)

* Remove unnecessary slash in curl command

* bundle update

* Fix rubocop errors

spec/factories/channel/facebook_pages.rb

@@ -1,7 +1,7 @@
 # frozen_string_literal: true
 
 FactoryBot.define do
-  factory :channel_facebook_page, class: Channel::FacebookPage do
+  factory :channel_facebook_page, class: 'Channel::FacebookPage' do
     name { Faker::Name.name }
     page_access_token { SecureRandom.uuid }
     user_access_token { SecureRandom.uuid }