Bug 19181: Change to use ENV, fix login and passwords

Bug 19181: Change to use ENV, fix login and passwords

The kohadevbox has admin/admin set, so for testing when
creating the initial superuser, if you wish to minimize
effort, use admin/admin. Otherwise, make sure to:
export KOHA_USER={whatever your user is}
export KOHA_PASS={whatever your password is}
before attempting to run the test.

Also, this test was failing because of a validation check on
the passwords requiring uppercase letters, lowercase letters,
and numbers. Changed the sample data passwords to fix.

Signed-off-by: Mark Tompsett <mtompset@hotmail.com>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>