Remove all email settings, default is ok.
Remove all email settings, default is ok.

By default, travis-ci will email the committer who broke the
build, which seem acceptable.
https://docs.travis-ci.com/user/notifications/

matyasselmeci/htcondor-ce,djw8605/htcondor-ce,matyasselmeci/htcondor-ce,brianhlin/htcondor-ce,brianhlin/htcondor-ce,bbockelm/htcondor-ce,opensciencegrid/htcondor-ce,djw8605/htcondor-ce,opensciencegrid/htcondor-ce,bbockelm/htcondor-ce,brianhlin/htcondor-ce,djw8605/htcondor-ce,opensciencegrid/htcondor-ce,bbockelm/htcondor-ce,matyasselmeci/htcondor-ce