Make rake jasmine:ci run specs correctly.

- Will replace rake core_specs.
- Remove obsolete dependencies & files -- most of these were for build tasks we
  are no longer using. Notably, rspec and spec_helper were deleted.

spec/javascripts/performance/performance_test.js

@@ -0,0 +1,10 @@
+describe("performance", function() {
+  for (var i = 0; i < 10000; i++) {
+    it("should pass", function() {
+      expect(true).toBe(true);
+    });
+    it("should fail", function() {
+      expect(true).toBe(false);
+    });
+  }
+});