Revert "build(deps): update RxJs to 5.0.0-rc.4 (#2905)"

This reverts commit 533f1b5.

Author: wardbell

public/docs/_examples/package.json

@@ -30,7 +30,7 @@
     "rollup": "^0.36.0",
     "rollup-plugin-node-resolve": "^2.0.0",
     "rollup-plugin-uglify": "^1.0.1",
-    "rxjs": "5.0.0-rc.4",
+    "rxjs": "5.0.0-beta.12",
     "systemjs": "0.19.39",
     "zone.js": "^0.6.25"
   },