Make sure user seed sets current user to superadmin

[therebelrobot]

@therebelrobot commented on Wed Apr 20 2016

Description

When reseeding users, the main superadmin gets wiped away and can no longer be admin (unles changes are done in DB). Refer brigadehub/brigadehub#189 (comment)

This could be tricky to pull off. Maybe an environment variable for your username? Maybe a standing list of the contributors in the seeds file? Something to look into.

cc @spiffysparrow