updating post_sync action
* moving to v2 controller
* adding support for a secret token
* removing http header guessing
Merge pull request #3722 from jlsherrill/post_sync

updating post_sync action
Remove code that has been replaced by bastion/v2 APIs.

Delete several old and unused UI controllers, views,
javascript files, styles, and tests as well as removing
unused functionality from remaining bastion-only UI controllers.