wmatrix: Scripts for setting up without user

Export DB passwords from config with export_passwords.py.
Change createusers and (raw)recreate to use these environment variables
rather than command-line arguments.

BUG=chromium:756604
TEST=watch logs

Change-Id: I4e4f9eaa1e0e53130a87aee7a8cfac1796a6a37b
Reviewed-on: https://chromium-review.googlesource.com/865715
Commit-Ready: Jacob Kopczynski <jkop@chromium.org>
Tested-by: Jacob Kopczynski <jkop@chromium.org>
Reviewed-by: Allen Li <ayatane@chromium.org>
4 files changed