tlbuild: CI testing on Travis-CI

 
 9.3 CI testing on Travis-CI
 ===========================
 
 The 'source' tree of TeX Live contains a top-level file '.travis.yml'
 which controls the automatic testing on Travis-CI. _admin_ has
 registered with Travis-CI and allowed access to the Github's 'TeX-Live'
 organization's 'texlive-source' repository.  The default settings are to
 build the last commit of each push.  No further action is necessary on
 Travis-CI.
 
    If changes have been pushed via the cron job above, Travis-CI will
 automatically checkout the last pushed commit and try building it.