Configured Yard and RSpec rake tasks

.gitignore

@@ -2,3 +2,4 @@
 .bundle
 Gemfile.lock
 pkg/*
+/doc

.rspec

@@ -1 +1,3 @@
 --colour
+-Ilib
+-Ispec

Gemfile

@@ -21,3 +21,7 @@ group :development do
   gem 'ripl-rails',        require: 'ripl/rails'
   gem 'ripl-rocket',       require: 'ripl/rocket'
 end
+
+group :documentation do
+  gem 'yard'
+end

Rakefile

@@ -1 +1,21 @@
 require 'bundler/gem_tasks'
+
+begin
+  require 'yard'
+  YARD::Rake::YardocTask.new(:doc)
+rescue LoadError
+  task :doc do
+    abort "YARD is not available. In order to run yardoc, you must: gem install yard"
+  end
+end
+
+begin
+  require 'rspec/core/rake_task'
+  RSpec::Core::RakeTask.new(:spec)
+rescue LoadError
+  task :spec do
+    abort "RSpec is not available. In order to run specs, you must: gem install rspec"
+  end
+end
+
+task default: :spec