Rakefile in rake-12.3.0 vs Rakefile in rake-12.3.1

@@ -7,28 +7,31 @@
 # MIT-LICENSE for details.
 
 lib = File.expand_path("../lib", __FILE__)
 $LOAD_PATH.unshift(lib) unless $LOAD_PATH.include?(lib)
 
-require "bundler/gem_tasks"
-require "rake/testtask"
-require "rdoc/task"
+begin
+  require "bundler/gem_tasks"
+rescue LoadError
+end
 
+require "rake/testtask"
 Rake::TestTask.new(:test) do |t|
   t.libs << "test"
   t.verbose = true
   t.test_files = FileList["test/**/test_*.rb"]
 end
 
+require "rdoc/task"
 RDoc::Task.new do |doc|
   doc.main   = "README.rdoc"
   doc.title  = "Rake -- Ruby Make"
   doc.rdoc_files = FileList.new %w[lib MIT-LICENSE doc/**/*.rdoc *.rdoc]
   doc.rdoc_dir = "html"
 end
 
 task ghpages: :rdoc do
-  `git checkout gh-pages`
+  %x[git checkout gh-pages]
   require "fileutils"
   FileUtils.rm_rf "/tmp/html"
   FileUtils.mv "html", "/tmp"
   FileUtils.rm_rf "*"
   FileUtils.cp_r Dir.glob("/tmp/html/*"), "."