Clean up generator for generator specs

Use singular name to match the generator name and use the generator name
in the spec description.

Also clean up an extra whitespace and empty line in the template.

lib/generators/rspec/generator/generator_generator.rb

@@ -4,7 +4,7 @@ module Rspec
   module Generators
     # @private
     class GeneratorGenerator < Base
-      class_option :generator_specs, type: :boolean, default: true,  desc: "Generate generator specs"
+      class_option :generator_specs, type: :boolean, default: true, desc: 'Generate generator specs'
 
       def generate_generator_spec
         return unless options[:generator_specs]
@@ -17,7 +17,7 @@ def template_name
       end
 
       def filename
-        "#{table_name}_generator_spec.rb"
+        "#{file_name}_generator_spec.rb"
       end
     end
   end

lib/generators/rspec/generator/templates/generator_spec.rb

@@ -1,6 +1,5 @@
 require 'rails_helper'
 
-RSpec.describe "<%= class_name.pluralize %>", <%= type_metatag(:generator) %> do
-
+RSpec.describe "<%= class_name %>Generator", <%= type_metatag(:generator) %> do
   pending "add some scenarios (or delete) #{__FILE__}"
 end