Deprecate Travis Bot from fbsource repos

Summary:
Remove travis webhook notification from repos
- redex
- gloo
- rsocket-js
- tgnms ?
- relay

Moving away from Travis Bot to automatic Task assignment on external CI test failures (https://fb.workplace.com/groups/1662633360725440/permalink/2399873220334780/)

Reviewed By: int3

Differential Revision: D16993379

fbshipit-source-id: cf7447e6f5b30f82d06d8d8ced82a9139a92941f

Author: Chris Lüer

.travis.yml

@@ -1,7 +1,7 @@
 sudo: required
 language: cpp
 compiler: gcc-5
-dist: xenial 
+dist: xenial
 
 before_install:
   - sudo apt-get install -y
@@ -23,6 +23,3 @@ before_install:
 
 script:
   - autoreconf -ivf && ./configure CXX='g++-5' && make -j4
-
-notifications:
-  webhooks: https://code.facebook.com/travis/webhook/