More v1 edits

A significant amount of culling has happened here.

* **Updating a User**: Several user fields were removed that aren't required for CGG or the first release of mobile apps
* **Report Backs/Sign Ups**: Previously I was suggesting that we store these items as dates (last created/updated I guess). But looking at how we store them in Drupal and how the Drupal Content API works, returning the `rbid` and `sid` seems to make more sense.
* **Logout**: Removing the need to submit a user identifier of some sort. It'll just look for the session token (or whatever we use) to figure out who to logout.
* Also worth noting that all the old stuff has just been moved into a v2 folder, so that stuff I've removed can still be on-deck for later.

cc: @aaronschachter @DeeZone 
https://github.com/DoSomething/dosomething/wiki/API#campaign-signup

These endpoints are in code, but not enabled on prod.  Had set them up for if/when we refactor the SMS Reportbacks to post to the Drupal API (vs using current `dosomething_sms` / `conductor_sms` code)