Added Github authentication option, disabled by default with enable options in settings.

spec/views/omniauth_callbacks/complete.html.erb_spec.rb

@@ -37,6 +37,18 @@ describe "users/omniauth_callbacks/complete.html.erb" do
     rendered_data["auth_provider"].should eq("OpenId")
     rendered_data["awaiting_activation"].should eq(true)
   end
+
+  it "renders github data " do
+    assign(:data, {:username =>"username", :auth_provider=>"Github", :awaiting_activation=>true})
+
+    render
+
+    rendered_data = JSON.parse(rendered.match(/window.opener.Discourse.authenticationComplete\((.*)\)/)[1])
+
+    rendered_data["username"].should eq("username")
+    rendered_data["auth_provider"].should eq("Github")
+    rendered_data["awaiting_activation"].should eq(true)
+  end
   
 end