Cleanup the travis yaml file. (#520)
Cleanup the travis yaml file. (#520)

Part of the fixes for #19. Some of the comments were out of date,
also the order of the environment variables did not make sense.

Put each environment variable in its own line.

Thanks to @houglum for the idea, much better I think.

googleapis/google-cloud-cpp,googleapis/google-cloud-cpp,googleapis/google-cloud-cpp,googleapis/google-cloud-cpp