Deprecating Travis Bot files and configuration

Summary:
Deprecate Travis Bot: this touches
- the webhook
- removes it from automated deprecation warning comments on diffs
- Remove rules and triggers
- Script controller

Individual repo settings:
- draft-js webhook configuration
- hack webhook configuration

[TODO]: add post/documentation about move from Travis Bot to Task Notification here

Reviewed By: yns88

Differential Revision: D16993364

fbshipit-source-id: f233e6a478215d5328a2fa33f71888f74d62b839

.travis.yml

@@ -64,4 +64,3 @@ notifications:
       - mr.kev@me.com
     on_success: change # send a notification when the build status changes
     on_failure: always # always send a notification
-  webhooks: https://code.facebook.com/travis/webhook/