$ sudo gem install dm-postgres-adapter
Successfully installed dm-postgres-adapter-1.2.0
1 gem installed

$ sudo bundle exec rake snorby:setup
No time_zone specified in snorby_config.yml; detected time_zone:
America/Chicago
rake aborted!
*cannot load such file -- dm-postgres-adapter*
Tasks: TOP => snorby:setup => environment
(See full trace by running task with --trace)