Check also for enterprise version when setting auth options for pusher
Check also for enterprise version when setting auth options for pusher

At the moment we set both pro and enterprise options for travis
enterprise, but at some point we would like to set only enterprise, so
this will future proof the code.

fotinakis/travis-web,fotinakis/travis-web,fotinakis/travis-web,fotinakis/travis-web,travis-ci/travis-web,travis-ci/travis-web,travis-ci/travis-web,travis-ci/travis-web