Fix build failure with Ruby 1.9.3

Gemfile

@@ -18,7 +18,7 @@ group :development, :test do
   # https://github.com/rspec/rspec-core/pull/2197
   gem 'rake',      '~> 11.0'
   gem 'simplecov', '~> 0.7'
-  gem 'rubocop',   '~> 0.47.1'
+  gem 'rubocop',   '~> 0.47.1' unless RUBY_VERSION.start_with?('1.')
 end
 
 group :development do

Rakefile

@@ -1,12 +1,17 @@
 require 'bundler/setup'
 require 'bundler/gem_tasks'
-require 'rubocop/rake_task'
 require 'rspec/core/version'
 
-RuboCop::RakeTask.new(:style)
+unless RUBY_VERSION.start_with?('1.')
+  require 'rubocop/rake_task'
+  RuboCop::RakeTask.new(:style)
+end
 
 Dir['tasks/**/*.rake'].each do |path|
   load(path)
 end
 
-task default: %w(spec style readme)
+default_tasks = ['spec']
+default_tasks << 'style' unless RUBY_VERSION.start_with?('1.')
+default_tasks << 'readme'
+task default: default_tasks

tasks/ci.rake

@@ -3,7 +3,7 @@
 tasks = %w(spec)
 
 if RSpec::Core::Version::STRING.start_with?('2.14') && RUBY_ENGINE != 'jruby'
-  tasks << 'style' if RUBY_VERSION >= '2.0.0'
+  tasks << 'style' unless RUBY_VERSION.start_with?('1.')
   tasks.concat(%w(readme:check test:all))
 end