Better log output for Saucelabs connect tunnel #27691

Jobs which are unable to even establish a Saucelabs tunnel instance, just print out dots for 10 minutes until Travis terminates the job.

This is not helpful because usually this happens if the API rate limit has been exceeded, and it would be good to log this into the console. Additionally it might be good to add a timeout of ~2 minutes since we don't want Travis to terminate the job, and rather print the log output before exiting.

See: https://travis-ci.org/angular/angular/jobs/468233060#L692

We might be able to just re-add a log file by using stdout and stderr instead of the Saucelabs --logfile option (as this is always verbose and can overwhelm travis)