Fix all Style/RedundantSelf rubocop issues

app/models/concerns/graphqlable.rb

@@ -4,33 +4,33 @@ module Graphqlable
   class_methods do
 
     def graphql_field_name
-      self.name.gsub('::', '_').underscore.to_sym
+      name.gsub('::', '_').underscore.to_sym
     end
 
     def graphql_field_description
-      "Find one #{self.model_name.human} by ID"
+      "Find one #{model_name.human} by ID"
     end
 
     def graphql_pluralized_field_name
-      self.name.gsub('::', '_').underscore.pluralize.to_sym
+      name.gsub('::', '_').underscore.pluralize.to_sym
     end
 
     def graphql_pluralized_field_description
-      "Find all #{self.model_name.human.pluralize}"
+      "Find all #{model_name.human.pluralize}"
     end
 
     def graphql_type_name
-      self.name.gsub('::', '_')
+      name.gsub('::', '_')
     end
 
     def graphql_type_description
-      (self.model_name.human).to_s
+      (model_name.human).to_s
     end
 
   end
 
   def public_created_at
-    self.created_at.change(min: 0)
+    created_at.change(min: 0)
   end
 
 end