Change sender_id to contact_id in conversations (#167)

* change sender_id to contact_id in conversations

* Fix failing tests

* Fix seeds

* fix specs

* Fix issues in facebook messenger

app/models/account.rb

@@ -5,7 +5,7 @@ class Account < ApplicationRecord
   has_many :inboxes, dependent: :destroy
   has_many :conversations, dependent: :destroy
   has_many :contacts, dependent: :destroy
-  has_many :facebook_pages, dependent: :destroy
+  has_many :facebook_pages, dependent: :destroy, class_name: '::Channel::FacebookPage'
   has_many :telegram_bots, dependent: :destroy
   has_many :canned_responses, dependent: :destroy
   has_one :subscription, dependent: :destroy

app/models/channel/facebook_page.rb

@@ -12,7 +12,7 @@ module Channel
     before_destroy :unsubscribe
 
     def name
-      `Facebook`
+      'Facebook'
     end
 
     private

app/models/contact.rb

@@ -6,7 +6,7 @@ class Contact < ApplicationRecord
 
   belongs_to :account
   belongs_to :inbox
-  has_many :conversations, dependent: :destroy, foreign_key: :sender_id
+  has_many :conversations, dependent: :destroy
   mount_uploader :avatar, AvatarUploader
 
   def push_event_data

app/models/conversation.rb

@@ -13,7 +13,7 @@ class Conversation < ApplicationRecord
   belongs_to :account
   belongs_to :inbox
   belongs_to :assignee, class_name: 'User', optional: true
-  belongs_to :sender, class_name: 'Contact'
+  belongs_to :contact
 
   has_many :messages, dependent: :destroy, autosave: true