Update CONTRIBUTING.md

Updating doc to point to the brand new CLA form at https://code.facebook.com/cla

CONTRIBUTING.md

@@ -27,7 +27,7 @@ The core team will be monitoring for pull requests. When we get one, we'll run s
 
 In order to accept your pull request, we need you to submit a CLA. You only need to do this once, so if you've done this for another Facebook open source project, you're good to go. If you are submitting a pull request for the first time, just let us know that you have completed the CLA and we can cross-check with your GitHub username.
 
-Complete your CLA here: <https://developers.facebook.com/opensource/cla>
+Complete your CLA here: <https://code.facebook.com/cla>
 
 ## Bugs