Fix all Style/RedundantSelf rubocop issues

app/models/user.rb

@@ -169,7 +169,7 @@ class User < ActiveRecord::Base
     comments_ids = Comment.where(user_id: id).pluck(:id)
     proposal_ids = Proposal.where(author_id: id).pluck(:id)
 
-    self.hide
+    hide
 
     Debate.hide_all debates_ids
     Comment.hide_all comments_ids
@@ -177,7 +177,7 @@ class User < ActiveRecord::Base
   end
 
   def erase(erase_reason = nil)
-    self.update(
+    update(
       erased_at: Time.current,
       erase_reason: erase_reason,
       username: nil,
@@ -191,7 +191,7 @@ class User < ActiveRecord::Base
       confirmed_phone: nil,
       unconfirmed_phone: nil
     )
-    self.identities.destroy_all
+    identities.destroy_all
   end
 
   def erased?
@@ -201,17 +201,17 @@ class User < ActiveRecord::Base
   def take_votes_if_erased_document(document_number, document_type)
     erased_user = User.erased.where(document_number: document_number).where(document_type: document_type).first
     if erased_user.present?
-      self.take_votes_from(erased_user)
+      take_votes_from(erased_user)
       erased_user.update(document_number: nil, document_type: nil)
     end
   end
 
   def take_votes_from(other_user)
     return if other_user.blank?
-    Poll::Voter.where(user_id: other_user.id).update_all(user_id: self.id)
-    Budget::Ballot.where(user_id: other_user.id).update_all(user_id: self.id)
-    Vote.where("voter_id = ? AND voter_type = ?", other_user.id, "User").update_all(voter_id: self.id)
-    self.update(former_users_data_log: "#{self.former_users_data_log} | id: #{other_user.id} - #{Time.current.strftime('%Y-%m-%d %H:%M:%S')}")
+    Poll::Voter.where(user_id: other_user.id).update_all(user_id: id)
+    Budget::Ballot.where(user_id: other_user.id).update_all(user_id: id)
+    Vote.where("voter_id = ? AND voter_type = ?", other_user.id, "User").update_all(voter_id: id)
+    update(former_users_data_log: "#{former_users_data_log} | id: #{other_user.id} - #{Time.current.strftime('%Y-%m-%d %H:%M:%S')}")
   end
 
   def locked?
@@ -223,7 +223,7 @@ class User < ActiveRecord::Base
   end
 
   def self.username_max_length
-    @@username_max_length ||= self.columns.find { |c| c.name == 'username' }.limit || 60
+    @@username_max_length ||= columns.find { |c| c.name == 'username' }.limit || 60
   end
 
   def self.minimum_required_age
@@ -257,10 +257,10 @@ class User < ActiveRecord::Base
 
   def send_oauth_confirmation_instructions
     if oauth_email != email
-      self.update(confirmed_at: nil)
-      self.send_confirmation_instructions
+      update(confirmed_at: nil)
+      send_confirmation_instructions
     end
-    self.update(oauth_email: nil) if oauth_email.present?
+    update(oauth_email: nil) if oauth_email.present?
   end
 
   def name_and_email
@@ -274,11 +274,11 @@ class User < ActiveRecord::Base
   def save_requiring_finish_signup
     begin
       self.registering_with_oauth = true
-      self.save(validate: false)
+      save(validate: false)
     # Devise puts unique constraints for the email the db, so we must detect & handle that
     rescue ActiveRecord::RecordNotUnique
       self.email = nil
-      self.save(validate: false)
+      save(validate: false)
     end
     true
   end
@@ -311,7 +311,7 @@ class User < ActiveRecord::Base
   private
 
     def clean_document_number
-      self.document_number = self.document_number.gsub(/[^a-z0-9]+/i, "").upcase if self.document_number.present?
+      self.document_number = document_number.gsub(/[^a-z0-9]+/i, "").upcase if document_number.present?
     end
 
     def validate_username_length