Rakefile in ably-0.6.2 vs Rakefile in ably-0.7.0

@@ -1,14 +1,32 @@
-require "bundler/gem_tasks"
+require 'bundler/gem_tasks'
+require 'json'
 
-require "yard"
+require 'yard'
 YARD::Rake::YardocTask.new
 
 begin
   require 'rspec/core/rake_task'
 
-  RSpec::Core::RakeTask.new(:spec)
+  rspec_task = RSpec::Core::RakeTask.new(:spec)
 
   task :default => :spec
+
+  namespace :doc do
+    desc 'Generate Markdown Specification from the RSpec public API tests'
+    task :spec do
+      ENV['TEST_LIMIT_PROTOCOLS'] = JSON.dump({ msgpack: 'JSON and MsgPack' })
+
+      rspec_task.rspec_opts = %w(
+        --require ./spec/support/markdown_spec_formatter
+        --order defined
+        --tag ~api_private
+        --format documentation
+        --format Ably::RSpec::MarkdownSpecFormatter
+      ).join(' ')
+
+      Rake::Task[:spec].invoke
+    end
+  end
 rescue LoadError
-  # no rspec available
+  # RSpec not available
 end