Disable suggestion of RuboCop extensions and update RSpec describe in…

… json_spec.rb

.rubocop.yml

@@ -4,6 +4,7 @@ require:
   - rubocop-rspec
 AllCops:
   NewCops: enable
+  SuggestExtensions: false
   Exclude:
     - db/schema.rb
     - db/views_schema.rb

spec/resource_tools/json_spec.rb

@@ -2,9 +2,9 @@
 
 require 'rails_helper'
 
-RSpec.describe ResourceTools::Json::Handler do # rubocop:todo RSpec/FilePath
+RSpec.describe 'ResourceTools::Json::Handler' do
   let(:json_class) do
-    Class.new(described_class) do
+    Class.new(ResourceTools::Json::Handler) do
       translate('key' => 'translated')
     end
   end