Fix RSpec 4 shared context inclusion

Starting from RSpec 4, the implicit shared context inclusion, when a
shared context would have been included to an example if the example has
matching metadata, is not the case anymore.

See:
 - rspec/rspec-core#2834
 - rspec/rspec-core#2832
 - rspec/rspec-core#2878

spec/rubocop/cli/autocorrect_spec.rb

@@ -1,8 +1,10 @@
 # frozen_string_literal: true
 
-RSpec.describe 'RuboCop::CLI --autocorrect', :isolated_environment do # rubocop:disable RSpec/DescribeClass
+RSpec.describe 'RuboCop::CLI --autocorrect' do # rubocop:disable RSpec/DescribeClass
   subject(:cli) { RuboCop::CLI.new }
 
+  include_context 'isolated environment'
+
   include_context 'when cli spec behavior'
 
   context 'when corrects `RSpec/Capybara/CurrentPathExpectation` with ' \

spec/spec_helper.rb

@@ -34,6 +34,10 @@ module SpecHelper
   config.raise_on_warning = true
 
   config.include(ExpectOffense)
+
+  config.include_context 'with default RSpec/Language config', :config
+  config.include_context 'config', :config
+  config.include_context 'smoke test', type: :cop_spec
 end
 
 $LOAD_PATH.unshift(File.join(File.dirname(__FILE__), '..', 'lib'))