Refactoring the code for pub sub (#155)

- We were using the attribute name 'channel' to store pubsub tokens, which was confusing.
- switched to faker from ffaker
- spec for contact.rb

app/models/contact.rb

@@ -1,5 +1,7 @@
 class Contact < ApplicationRecord
-
+  
+  #Used by the pusher/PubSub Service we use for real time communications
+  has_secure_token :pubsub_token
   validates :account_id, presence: true
   validates :inbox_id, presence: true
 
@@ -8,21 +10,13 @@ class Contact < ApplicationRecord
   has_many :conversations, dependent: :destroy, foreign_key: :sender_id
   mount_uploader :avatar, AvatarUploader
 
-  before_create :set_channel
-
   def push_event_data
     {
       id: id,
       name: name,
       thumbnail: avatar.thumb.url,
       channel: inbox.try(:channel).try(:name),
-      chat_channel: chat_channel
+      pubsub_token: pubsub_token
     }
   end
-
-  def set_channel
-    begin
-    self.chat_channel = SecureRandom.hex
-    end while self.class.exists?(chat_channel: chat_channel)
-  end
 end

app/models/user.rb

@@ -11,6 +11,9 @@ class User < ApplicationRecord
     :validatable, 
     :confirmable
 
+  #Used by the pusher/PubSub Service we use for real time communications
+  has_secure_token :pubsub_token
+
   validates_uniqueness_of :email, scope: :account_id
   validates :email, presence: true
   validates :name, presence: true
@@ -26,7 +29,6 @@ class User < ApplicationRecord
   has_many :assigned_inboxes, through: :inbox_members, source: :inbox
   has_many :messages
 
-  before_create :set_channel
   before_validation :set_password_and_uid, on: :create
 
   accepts_nested_attributes_for :account
@@ -42,12 +44,6 @@ class User < ApplicationRecord
     super(options).merge(confirmed: confirmed?, subscription: account.try(:subscription).try(:summary) )
   end
 
-  def set_channel
-    begin
-    self.channel = SecureRandom.hex
-    end while self.class.exists?(channel: channel)
-  end
-
   def notify_creation
     Rails.configuration.dispatcher.dispatch(AGENT_ADDED, Time.zone.now, account: self.account)
   end