Add spec for the 'atom' protocol URLs.

spec/atom-protocol-handler-spec.coffee

@@ -0,0 +1,17 @@
+$ = require 'jquery'
+fs = require 'fs'
+path = require 'path'
+
+describe '"atom" protocol URL', ->
+  it 'sends the file relative in the package as response', ->
+    called = false
+    callback = -> called = true
+    $.ajax
+      url: 'atom://async/package.json'
+      success: callback
+      # In old versions of jQuery, ajax calls to custom protocol would always
+      # be treated as error eventhough the browser thinks it's a success
+      # request
+      error: callback
+
+    waitsFor 'request to be done', -> called is true