avoid hard coding the postgres username

[swills]

Closes issue #4

Pull request should be right this time. Thanks!

[davepacheco]

Thanks for doing this. How was this tested?

[swills]

@yunong can you point me at the lint/style checker?

[swills]

@davepacheco Tested manually on FreeBSD. If there are tests that need to be run, please let me know where and I will try to run them, though I don't have a complete SDC environment up yet, so if that is required I may not be able to run it.

[yunong]

@swills The test suite and lint/style checkers are run via npm test. Thanks for the patch!

[swills]

Style issues fixed. The tests as far as they can right now, though they hard code the username as well, ironically, so there's more to do. They also hard code some commands, such as zonename, useradd, ctrun.