vrsmn% heroku rake db:migrate
(in /app)
Error while setting omniauth providers: #<ActiveRecord::StatementInvalid: PGError: ERROR:  relation "oauth_providers" does not exist
: SELECT "oauth_providers".* FROM "oauth_providers">
rake aborted!
PGError: ERROR:  relation "configurations" does not exist
:             SELECT a.attname, format_type(a.atttypid, a.atttypmod), d.adsrc, a.attnotnull
              FROM pg_attribute a LEFT JOIN pg_attrdef d
                ON a.attrelid = d.adrelid AND a.attnum = d.adnum
             WHERE a.attrelid = '"configurations"'::regclass
               AND a.attnum > 0 AND NOT a.attisdropped
             ORDER BY a.attnum

(See full trace by running task with --trace)