DROP TABLE users;
DROP TABLE credentials;
DROP TABLE permissions;

INFO  [SharedPool-Worker-1] 2016-07-13 14:09:32,400 MigrationManager.java:401 - Drop table 'system_auth/users'
INFO  [SharedPool-Worker-1] 2016-07-13 14:10:14,411 MigrationManager.java:401 - Drop table 'system_auth/credentials'
INFO  [SharedPool-Worker-1] 2016-07-13 14:10:20,269 MigrationManager.java:401 - Drop table 'system_auth/permissions'