Re-implemented all development Rake tasks in Thor. Now actually tested.

Fixes:
* https://www.pivotaltracker.com/story/show/25484287 & https://github.com/pivotal/jasmine/issues/183
* https://www.pivotaltracker.com/story/show/25485401 & https://github.com/pivotal/jasmine/issues/189
* https://www.pivotaltracker.com/story/show/25485953 & https://github.com/pivotal/jasmine/issues/159

spec/tasks/build_github_pages_spec.rb

@@ -0,0 +1,56 @@
+require 'spec_helper.rb'
+
+describe "Build Github Pages task" do
+
+  let(:pages_dir) { File.join(Dir.tmpdir, 'pages') }
+  let(:jasmine_dev) { JasmineDev.new }
+
+  before do
+    reset_dir pages_dir
+  end
+
+  describe "when the Github pages submodule is not present" do
+    before do
+      jasmine_dev.should_receive(:has_pages_submodule?).and_return(false)
+
+      @output = capture_output { jasmine_dev.build_github_pages pages_dir }
+    end
+
+    it "should tell the user the task is running" do
+      @output.should match(/Building Github Pages/)
+    end
+
+    it "should prompt the user to install the submodule" do
+      @output.should match(/Submodule for Github Pages isn't present/)
+    end
+  end
+
+  describe "when the Github pages submodule is present" do
+    before do
+      jasmine_dev.should_receive(:has_pages_submodule?).and_return(true)
+
+      @output = capture_output { jasmine_dev.build_github_pages pages_dir }
+    end
+
+    it "should tell the user the task is running" do
+      @output.should match(/Building Github Pages/)
+    end
+
+    it "should tell the user the pages are built" do
+      @output.should match(/Congratulations, project dumped to/)
+    end
+
+    it "should copy the pages output to the requested diretory" do
+      Dir.chdir File.join(pages_dir, 'pages_output') do
+        pages = Dir.glob(File.join('**', '*'))
+
+        pages.should include('download.html')
+        pages.should include('index.html')
+        pages.should include(File.join('images', 'jasmine_logo.png'))
+        pages.should include(File.join('images', 'pivotal_logo.gif'))
+        pages.should include(File.join('css', 'pygments.css'))
+        pages.should include(File.join('css', 'screen.css'))
+      end
+    end
+  end
+end