http://qiita.com/_daisuke/items/13996621cf51f835494b
ユーザ(role)追加
$ createuser -P myuser
データベース作成 / -O はowner
$ createdb nypd_development -O myuser
これでrake db:migrateすればいい
config/database.yml
default: &default adapter: postgresql encoding: unicode pool: 5 development: <<: *default database: myapp_development username: myuser password: myuser host: localhost port: 5432 test: <<: *default database: myapp_test