define our own clean/clobber tasks

Rakefile.rb

@@ -7,11 +7,8 @@ end
 
 require "bundler/gem_tasks"
 require "rspec/core/rake_task"
-require "rake/clean"
 require "yard"
 
-CLEAN.include 'build_test_run'
-
 RSpec::Core::RakeTask.new(:spec)
 
 YARD::Rake::YardocTask.new do |yard|
@@ -19,3 +16,11 @@ YARD::Rake::YardocTask.new do |yard|
 end
 
 task :default => :spec
+
+task :clean do
+  FileUtils.rm_rf(["build_test_run", "doc", "coverage"])
+end
+
+task :clobber => :clean do
+  FileUtils.rm_rf(["pkg"])
+end