Add and apply rubocop rules for empty lines

We were very inconsistent regarding these rules.

Personally I prefer no empty lines around blocks, clases, etc... as
recommended by the Ruby style guide [1], and they're the default values
in rubocop, so those are the settings I'm applying.

The exception is the `private` access modifier, since we were leaving
empty lines around it most of the time. That's the default rubocop rule
as well. Personally I don't have a strong preference about this one.


[1] https://rubystyle.guide/#empty-lines-around-bodies

lib/graph_ql/api_types_creator.rb

@@ -29,9 +29,7 @@ module GraphQL
     end
 
     def self.create_type(model, fields, created_types)
-
       created_types[model] = GraphQL::ObjectType.define do
-
         name        model.graphql_type_name
         description model.graphql_type_description
 
@@ -54,7 +52,6 @@ module GraphQL
             end
           end
         end
-
       end
     end
 

lib/graph_ql/query_type_creator.rb

@@ -2,7 +2,6 @@ require "graphql"
 
 module GraphQL
   class QueryTypeCreator
-
     def self.create(api_types)
       GraphQL::ObjectType.define do
         name "QueryType"
@@ -22,10 +21,8 @@ module GraphQL
             description model.graphql_pluralized_field_description
             resolve ->(object, arguments, context) { model.public_for_api }
           end
-
         end
       end
     end
-
   end
 end