remove staging server links

Author: jakewmeyer

CONTRIBUTING.md

@@ -8,11 +8,10 @@ covered, make sure to add a test for it.
 2. New Pull Requests will automatically trigger a Travis CI Build
 
 3. If the build fails, look at the [Build Logs](https://travis-ci.org/r-spacex/SpaceX-API).
-Changes will not be merged unless the build passes.
+Changes will not be merged unless the build passes
 
 4. If the build succeeds, the pull request will be merged, and automatically
-pushed to the staging server at [http://stage.spacexdata.com/v2/](http://stage.spacexdata.com/v2/) for a
-final check before promoting changes to production at [https://api.spacexdata.com/v2/](https://api.spacexdata.com/v2/).
+pushed to the production server at [https://api.spacexdata.com/v2/](https://api.spacexdata.com/v2/)
 
 ## Database additions / changes / updates