Fix some warnings

Author: David Rodríguez

spec/generators/rspec/install/install_generator_spec.rb

@@ -27,7 +27,7 @@ def require_rspec_rails
     match(/^require 'rspec\/rails'$/m)
   end
 
-  def use_transactional_fixtures
+  def have_transactional_fixtures_enabled?
     match(/config\.use_transactional_fixtures/m)
   end
 
@@ -70,7 +70,7 @@ def filter_rails_from_backtrace
 
     specify "with default fixture path" do
       run_generator
-      expect(rails_helper).to use_transactional_fixtures
+      expect(rails_helper).to have_transactional_fixtures_enabled?
     end
 
     specify "excluding rails gems from the backtrace" do
@@ -114,7 +114,7 @@ def filter_rails_from_backtrace
 
     it "does not include config.use_transactional_fixtures" do
       run_generator
-      expect(rails_helper).not_to use_transactional_fixtures
+      expect(rails_helper).not_to have_transactional_fixtures_enabled?
     end
 
     it "does not check use active record migration options" do

spec/spec_helper.rb

@@ -1,9 +1,5 @@
 require 'rails/all'
 
-class << RSpec
-  attr_writer :configuration
-end
-
 module RSpecRails
   class Application < ::Rails::Application
     self.config.secret_key_base = 'ASecretString' if config.respond_to? :secret_key_base